Abstract: A tray capable of being frictionally engaged to a support structure comprises a horizontally oriented planar base having an edge. A right-angle bracket has a horizontally oriented side. An edge of the horizontally oriented side of the right-angle bracket is coupled adjacent the edge of the base and extends in a direction parallel to a plane of the base. The right-angle bracket has a vertically oriented side coupled to the horizontally oriented side at a corner of the right-angle bracket and extending downward. A bracket is coupled to a bottom surface of the base and extends downward in the direction substantially normal to the base. This bracket is positioned opposite the right-angle bracket a horizontal distance sufficient to receive the support structure positioned therebetween. A screw comprising a handle at a first end of the screw and a shoe at a second end of the screw passes through a threaded hole in the bracket and extends toward the right-angle bracket.