that tray hooks onto your exterior entertainment center. open that compartment door, spread the "wings" on the tray and hook the rear support over the lip of the now open compartment door. the "wings" will support and steady the tray against the side of your Brave. we had the same thing on our '00 Suncruiser.
I’d posted exactly the same question. Well done those before me. We have put it up and it is definitely handy coming in and out of the door. It’s not much use for the entertainment center but great at the side of the door.
I cut my table size down, too tempting to overload the compartment hinges. Also the shelf can be utilized with compartment door latched relieving hinge stress. Where particle board cut was exposed I applied several coatings of exterior wood glue to prevent water absorption.
You can buy “edge tape” in multiple colour or wood types. Some can be steamed to go around bends. Iron it into place, file down the edges and it would look original