Abstract: A tray table assembly which can be positioned horizontally for use by a person in a chair. When not in use, the tray table can be folded against the side of the chair. A mount bracket is attached to the arm of the chair. Pin tracks are disposed in the mount bracket. A hinge bracket is attached to a tray table. Pin holes are disposed in the hinge bracket. The hinge bracket is pivotally engaged to the mount bracket by a clevis pin that extends through the pin holes and the pin tracks. The tray table can be moved from a first position where the tray table is maintained in a horizontal position, to a second position in which the tray table is free to rotate to the side of the chair. In the horizontal position, tabs on the hinge bracket engage slots in the mount bracket, thereby retaining the tray table in the horizontal position.