A clamping apparatus removably attachable to an elongate support such as a tray table latch on a seatback with a stowable tray table includes a pair of opposing hand grips slidably coupled to a clamp frame. Each hand grip includes a clamp jaw protruding from a back side of the clamp frame. A spring urges the hand grips apart and the clamp jaws toward one another. A flexible band attached to both hand grips is provided for suspending the clamp frame. When a person releases the opposing hand grips, the flexible band partially retracts into the clamp frame, drawing the frame against the latch, and the two clamp jaws grip opposite sides of the latch. Compressing the hand grips laterally toward one another extends the flexible band out of the clamp frame and displaces the two clamp jaws away from one another.