Abstract: An accessory device capable of being mounted on a ladder having hollow rungs includes a pair of primary support arms which are shaped to fit within rungs having flat top sides to prevent rotation of the primary arms therein. Secondary support arms are slidably extensible from the primary support arms to laterally position a tray assembly relative to one side of the ladder. A brace connected to the secondary support arms engages a tray assembly. The level of the tray relative to the slope of the ladder is adjusted by varying the position of arcuate slots found within a pair of flanges mounted on the bottom side of the tray relative to the brace. Thus, a user can adjust the level of the tray while keeping one or both hands on the tray for stability. The device may be mounted to either side of the ladder with the supporting arms and brace optionally remaining mounted on the ladder during transport and/or storage.