Attach the 1 1/2"-by-48" boards flat and flush with the edges of the 48"-by-25" board using 1" screws.
Measure 14 inches down each 1 1/2"-by-48" board and, using one hinge each, attach the 19" dowels on and parallel to the 48" boards.
Take two of the remaining four dowels and lay them 15 inches apart. Attach one 18" board across the ends of the dowels and perpendicular to the work space. Attach one 24" board at the other end of the dowels, also perpendicular, so that there is a 3 inch overhang on each side. Repeat with the remaining boards.
Set the two frames from step three on-edge, 22 inches apart, treating the 24" side as the feet. Place the seat assembly from step two into the frames, so that the bottoms of the Ts is in contact with the feet. Use screws to secure at all contact points.
Attach the 1 1/2"-by-48" boards flat and flush with the edges of the 48"-by-25" board using 1" screws.
Measure 14 inches down each 1 1/2"-by-48" board and, using one hinge each, attach the 19" dowels on and parallel to the 48" boards.
With the 19" dowels hanging free from the table top, center it on the arm rests of the chair. The 19" dowels should be 1 inch from from the ends of the arm rests.
On the opposite ends of the arms rests from the 19" dowels, attach the table top to the arm rests with the remaining two hinges.
When the table top is rotated back on the hinges, you should be able to rotate down the 19" dowels and they will rest on the arm rests, holding the table top/chair back in place.