If you have an opaque table, then you can't project from below.
From above, it might be quite difficult to fix the projector to the ceiling, or that may not be far enough away.
I would suggest fixing a mirror to the ceiling, and putting the projector facing up on a table next to the game table.
This will allow you to have a large projection on the table and you can access the projector easily.
Personally I think ceiling mirrors are nice anyway, and I would leave it there as a permanent feature between gaming sessions.
The other thing you could do is put your projector on a high shelf, and have a mirror just off the shelf suspended right in front of the projector.
This may be a lot harder, as mounting the mirror at the right angle could be difficult.
Either way, you would want to put something white on the table, experiment with a few things, perhaps a large piece of paper or even a whiteboard if you have one.
If you use paper or a whiteboard you could even draw extra information on it, the whiteboard would be better as it allows you to easily erase the info if you change settings.
If you wanted the draw and erase feature of a whiteboard, you could even experiment with white paper covered with a large piece of perspex (like you get from those huge cheap poster frames.