If you don't need the table you could just add a permanent top bunk. If you want to be able to use the table and have a top bunk you have to have a different support system for the table.A top bunk is normally hinged on a piece of wood hidden in the insulation just under the front window. If you're table is fastened to the same wall it interferes with lowering the top bunk as a backrest while usung the table. You have to use a pedestal support from the floor to the table like they used to do in van conversions so you can temporarily remove the table before lowering the top bunk, then replace the table. Most RV shops should have the 3 piece support, a receptacle fastened to the underside of the table, a receptacle fastened to the floor, and a tube to insert between the two. I believe they use piano hinge to anchor the top bunk just below the window. The top bunk is just a piece of plywood with foam and fabric cover. I think Scamp
recommend no more than 80 lbs on their top bunk. Before you start you might want to weigh the boys.