The Minor Conjuration ability given to Conjuration Wizards allows you to replicate non-magical object you have seen, so could you theoretically create your own spellbook, or even the spellbook of a powerful wizard, and prepare spells of of it? To bypass the "You would have to remember the whole book" solution, assume this wizard took the keen mind feat.
Makes a Copy of the Item
Minor Conjuration reads:
Starting at 2nd level when you select this school, you can use your action to conjure up an inanimate object in your hand or on the ground in an unoccupied space that you can see within 10 feet of you. This object can be no larger than 3 feet on a side and weigh no more than 10 pounds, and its form must be that of a nonmagical object that you have seen. The object is visibly magical, radiating dim light out to 5 feet.
- No Larger that 3 feet on each side - check.
- Weigh less than 10 pounds - check.
- nonmagical - See below.
- that you have seen - The one you have seen, not a type a facsimile of the one you seen - check.
Jeremy Crawford tweeted a ruling which at the time was an offical ruling (now unofficially) ruled that it is a magical facsimile:
Minor conjuration: object is 3 ft. on a side or less, period. Composition is DM's call. It's worth 0 gp; it's a magical facsimile.
Spell Books Are Non-Magical
The description of the Spellbook class feature reads:
At 1st level, you have a spellbook containing six 1st-level wizard spells of your choice. Your spellbook is the repository of the wizard spells you know, except your cantrips, which are fixed in your mind.
The spells that you add to your spellbook as you gain levels reflect the arcane research you conduct on your own, as well as intellectual breakthroughs you have had about the nature of the multiverse. You might find other spells during your adventures. You could discover a spell recorded on a scroll in an evil wizard’s chest, for example, or in a dusty tome in an ancient library.
The Book’s Appearance. Your spellbook is a unique compilation of spells, with its own decorative flourishes and margin notes. It might be a plain, functional leather volume that you received as a gift from your master, a finely bound gilt-edged tome you found in an ancient library, or even a loose collection of notes scrounged together after you lost your previous spellbook in a mishap.
The book description doesn't use the term magical in all of the descriptions of possible forms the book can take. Including the inks:
Rules as Intended
For each level of the spell, the process takes 2 hours and costs 50 gp. The cost represents material components you expend as you experiment with the spell to master it, as well as the fine inks you need to record it. Once you have spent this time and money, you can prepare the spell just like your other spells.
Jeremy Crawford also (now) unofficially ruled a spellbook isn't necessarily magical:
A normal spellbook or spellcasting focus is not a magic item. A magic one is possible, such as a magic staff.
So, together, we get an answer of yes. You can use Minor Conjuration to get a copy of a non-magical spellbook.
Would it be a Blank Book?
No. An object in D&D is defined:
For the purpose of these rules, an object is a discrete, inanimate item like a window, door, sword, book, table, chair, or stone, not a building or a vehicle that is composed of many other objects.
Words are not discrete items, so are not objects in themselves. They become a part of the book when they are written in them. Aruging otherwise would be arguing that if you targeted a book (an object) with spells that target one object like disintegrate or true polymorph, would somehow leave the words separate from the book.
No. Minor Conjuration would need to say “an exact replica of an object you've seen” or some other very precise wording, if it was capable of doing that. Instead, it allow you to conjure objects limited to the kinds of objects you've seen before:
its form must be that of a nonmagical object that you have seen.
… That is to say, it conjures an object by type, not by identity. You can conjure “a book” — even a large one with vellum pages like a spellbook has — but not a copy of a specific spellbook to get access to its contents.
If you're after a house rule which clarifies what you can and can't do with Minor Conjuration, I'd suggest following the example of the fabricate spell (PH p. 239 / SRD p. 140):
You also can’t use it to create items that ordinarily require a high degree of craftsmanship, such as jewelry, weapons, glass, or armor, unless you have proficiency with the type of artisan’s tools used to craft such objects.
So allow the conjurer to create anything they could otherwise have crafted for themselves, given time and nonmagical materials. Backgrounds providing tool proficiencies become an an important differentiator between one conjurer and the next.
Under the "if you could craft it, you can conjure it" house rule, the answers are as follows.
Could you create your own spellbook?
In short, yes -- as long as you could have conjured a blank spellbook to start with. While a blank spellbook would normally be an item that requires a high degree of craftsmanship, it doesn't actually need to be. It might be (PH p. 114):
[...] a loose collection of notes scrounged together after you lost your previous spellbook in a mishap.
All wizards can craft spellbook pages given just paper and ink, so no further tool proficiency is needed to craft "a loose collection of notes". If the conjurer happens to have relevant proficiencies (e.g. with calligraphy, forgery, or leatherworking tools) this merely allows conjuring a nicer spellbook.
Minor Conjuration could thus create a spellbook containing any of the spells the conjurer currently has memorized, since (PH p. 114):
If you lose your spellbook, you can [...] transcribe the spells that you have prepared into a new spellbook.
If the conjurer has one of her own spellbooks at hand to refer to, she could also duplicate any spells from that book.
Could you create the spellbook of a powerful wizard?
If the powerful wizard is you, then yes. :)
Otherwise, even with the powerful wizard's book in your possession, Minor Conjuration cannot duplicate spells within it, since undeciphered spells cannot be transcribed.
What about the Keen Mind feat?
According to the accepted answer for "To What Extent Can The Keen Mind Feat Replace a Wizard's Spellbook?", Keen Mind would allow Minor Conjuration to duplicate one of the conjurer's spellbooks entirely from memory, provided they had read its entire contents within the last month.
I believe the inks used in writing spells are at least semi-magical seeing how high the price is compared to regular ink. I'd say, you'd have the THEORY of the spell without the magic. You'd probably have to pay the full price of the ink to make the spells magical, with a chance to screw up as normal as you have NO IDEA of the spellwork woven into the characters written on the pages.
Also, you couldn't copy another wizard's spellbook unless you've read it... it would be a BLANK powerful spellbook.