It's called a Game Topper and it sits atop any existing table (of sufficient length). Pictured here is The Watson, 72" x 36" of gaming bliss. Even with the expanded map from 878 Vikings there is still ample room.
This thing is solid! Weighs as much as a couch but fits neatly in an exceptionally sturdy bag not much larger than my poker table top folded up. Which btw, if someone wants that let me know. I don't want or need that any more.