An accessory device for attachment to a folding step ladder includes a square or rectangular receiver frame that hingedly attaches to the top end of the ladder and a tray that is removably supported within the receiver frame. In a preferred embodiment, the receiver frame is attached with two or more hinges to the ladder and includes collapsible pivoting support arms on opposite sides extending between and connecting to the sides of the receiver frame and the ladder. In use, the receiver frame is supported horizontally, extending out from the top of the ladder, and is held by the support arms that lock into an extended position. When not in use, the receiver frame is folded down and collapsed against the side of the ladder for transport and storage.