Our round dining room table comfortably seats 8 people. Jeanine, already in planning mode for Thanksgiving and Christmas, asked if it would be possible to extend the seating for up to 12. Our table has a solid top with no provisions for an extension leaf so I decided to build one that mates along one half of the perimeter. I used 3/8″ thick Baltic Birch plywood in a three-layer stack-up. The top layer matches the existing table radius and extends the contour ~30″. The middle layer (pictured below) comprises the internal structure that create a torsion box when the bottom layer is glued to them. The result is a 1-1/8″ thick top that weighs the same as a 3/4″ top would and is substantially stiffer. I did not notice until just now, that the internal layer looks like a cat’s face. The squarish blocks are positioned to accept mounting screws for the legs and the curved pieces are leftovers from the cutouts. I will post another photo of the completed extension table when I have had a chance to mount the folding legs.