Got a table from Star Paper locally and was very impressed with their Laser Leveling system. It's the same laser leveling system used in construction, leveling picture frames. I guess it works on the principle of a gyro, because it needs no leveling by itself and project a level laser beam, both horizontal and vertical across the room. Using the horizontal beam and a Bottle of Coke placed on surface of slate, on can easily level a table.
By placing the bottle of coke on different points of slate, any variations on the horizontal beam will indicate a need to adjust the table. Anyway, using this technique, it took less than 5 minutes to level the table and then I tried rolling a ball on the bare slate in all directions, PERFECT!
Installation took about 2 hours and then we started playing right after and the installers left. Until now, the table is still perfectly level.