My Matilda's table measures 45" long by 18" wide.  It's made of 3/4" ply with a "mahogany-type" woodgrain face (which could be some sort of applied veneer).  The end which fits into the aft-bulkhead slot is square, of course and the forward end has rounded corners with about a 2" radius.

There is a slot on the forward edge which drops down over the keel housing, which is key to keeping things in place.  The slot measures 2 1/4 wide by 3  15/16 deep on the top surface and 4  1/4 on the bottom surface.  The resulting slope pretty much follows the angle of the keel housing.

 The portside edge of the slot is 9 3/4" from the portside edge of the table.  The starboard edge of the slot is 6" from the starboard edge of the table.

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