Already have a small lego table but son is outgrowing it. Would love to do this on a bigger size table for him. Would be good for a kid's playroom. If you did velcro to attach it, you could switch out the base plates maybe.
The coffee table top is GONNA get ruined anyways! :) Repaint a coffee table with chalk board paint. Draw a road, game boards, self portraits, work out homework problems, or just let the kids go wild. It will keep them entertained for hours.