I've got an idea for when I finally get a trailer of my own. Have a side mount swing down tire carrier, probably behind the passenger's side wheel. Triangular frame. Mount the spare between the swing out frame and the trailer side. When it swings down, have a pop out leg to hold it at 90 degrees. Then put a circle of plywood on top of the spare tire for a convenient table. Could also bolt the plywood to the spare so that it has it's own stowed place, and then you don't have to do anything to set it up once in camp. I've got it drawn up in sketch up, but no pictures of course, just a pipe dream. Concerns would be the extra weight behind the axle and off to one side of the trailer. And of course the strength of the frame in that particular area.