That may be a lever to move the lift up and down. A knee control would come as part of the machine not the table. A knee lifter controls the presser foot and the foot pedal controls speed of machine. Perhaps you could call Horn and ask about the panel. By looking at the knobs on the sides it may go inside the cabinet as a shelf. If you look closely at the drawers inside the cabinet they have the same knobs. Just a thought. I think you are missing some pieces!