I don't know if I'll actually build this design. In fact, even if I work up the gumption to try it - there would be many challenges for someone at my level - I'm sure the design will undergo many changes before it's built.
For right now I'm curious about the center section that lifts out. If it's made of solid wood (lets say oak), how much play would I need to allow around the perimeter? It would probably be 6" to 8" wide. Would a sixteenth be adequate?
Next, is this simply a stupid idea? Specifically, is the center piece likely to warp over time and not sit flat? I can't see using ply for this, as I like the decorative square holes, which would also be used to remove the cover.
As always, try to be gentle. :)