Abstract: A rotatable support assembly formed of pivotable sections has upper and lower surfaces and tapered end edges. A riding strip fabricated of an elastomeric material extends over the upper surface from tapered end edge to tapered end edge. A carousel assembly includes a fixed lower section, a rotatable upper section, and equally spaced rollers between the upper and lower sections. A locking assembly includes wells formed into the upper surface. A circular plate has an upper aperture and a locking tab with a lower aperture. The locking assembly also includes a pin extending through the upper and lower apertures. A coil spring between the apertures urges the pin downwardly into a locked orientation to preclude rotation of the support assembly.