Those are used when randomly creating magic items.
If you are a player, just disregard that column entirely. You won't ever need it.
If you are a GM, you can randomly determine magical items for treasure hordes by using those tables. To get the full use of the tables, you will need a copy of the Game Mastery Guide because not all of the tables can be reproduced online. However, if you want to randomly determine a certain type a treasure (a random magical weapon, a random scroll, etc.) then you should be okay with the online tables.
Here's an example of using the tables:
- Gary Miller, the GM, needs to randomly create a magical dagger for a treasure horde. For some reason, he created a magical dagger for his plot but never specified what exactly it did.
- By looking at the tables, he decides that a greator minor magic weapon is appropriate for his party.
- He rolls a d100 and gets a 72. On the greater minor magic weapon table, that is a +1 special ability.
- He rolls a d100 again to determine what the special ability will be. He rolls a 10 and consults the +1 special ability table. According to the table, that is the called ability.
- The process ends. The weapon is a Called Dagger.
There are other tables on the page that are basically for the same usage (for example, the special materials table). If you have the Game Mastery Guide, it will show you a process for linking all the tables together. That information is not available online.