A platform assembly is suitable for insertion and retention between a lower furniture support, such a boxspring of a bed, and an upper furniture support, such as a mattress of a bed. The platform assembly has a housing and a platform provided with foldable legs. When withdrawn from the housing with the legs in the unfolded position and resting on the floor, the platform is able to support a load, such as blankets, pillows, suitcases and the like, and even a pet or small child.