The pool tables have computerized hydrolics in the legs that keep them perfectly level at all times. It's really cool to watch. You'll see as the ship is rolling, even if only a tiny bit, the legs are moving up and down.
The problem with the tables (and probably why you don't see a lot of people playing), is:
Although the table is kept from moving while the ship is, there is nothing to keep YOU from moving with the ship. So the tables are level, but YOU AREN'T!!
It really makes it hard to aim and shoot.
Hope This Helps.
Darrell & Donna