If I've measured right, the pieced part of this Whirl-A-Jig quilt kit from Connecting Threads fits the surface of our oval table, except for a little bit of the corners that hang off:
I ordered extra background and blue fabrics, and am thinking of modifying the quilt something like this. The end curve probably will need to be more pronounced, but I can use a tablecloth that fits the table and make accurate templates of the curves):
To get the overhang consistent all around, the white may need to be deeper in the end curves than on the sides, but I'm thinking by the time it drapes, the difference may not be noticeable.
What do y'all think?