This room is located on third floor to the left of the stairs,  there is no other room in the house that is like it.  It shows remnants of the dumb waiter that came from the basement, through the kitchen and second floor (Railroad Room) and ended here.  Every wall in this room has plate rails, a good indication that the fine china was stored and displayed here.  Since the Ballroom was used for banquets it is very likely that the food was sent up on the dumb waiter, plated here and served in the ballroom.