By floating table I mean a way to eliminate the table "edges". So when a ship moves off the edge in one direction, everything get's adjusted so it stays on. Ripple pointed out the use of 'pinning' ships though, where you keep ships in certain spots to disallow the map from being moved to adjust for ship movement.
Floating tables means that you can't "put a ship in the corner" and wait there since the other fleet can simply go around the edge and you're sitting in the middle again.
(I was introduced to the concept with AoG's Wars. Except that used a Hex Map so it was easier to just move everything 6 hexes to in a direction.)