A table assembly structured for selective positioning between a conventional orientation and a gaming orientation, wherein the latter facilitates the playing of a game, such as billiards thereon. A plurality of side rails are connected to an under portion of a table top of the table assembly and movable between a stored position and an operative position which respectively define the conventional and gaming orientations. When in the stored position, the plurality of side rails are disposed in a primarily hidden location in order to enhance the table's appearance. A plurality of cover members may also be disposed in overlying, covering relation to the under portion and stored side rails. A positioning assembly includes a plurality of linkage structures movably supporting the plurality of side rails along a complex path of travel as the plurality of side rails move between the stored and operative positions.