well ok, here's a good project ...
this client bought the table above at an auction as 'half of a table', 'several years ago'.
when we got it, it was three pieces, the top, the leaf, and the base below,
no hinges and no instructions.
so this was the base .. nice carvings! we didn't think much about the hole until after we made some
half size pieces of cardboard and tried to figure out where the pivot point for the main top was.
bingo! the theoretical pivot point was somewhere in the hole!
so we filled in the hole and attached the top to the base with another circular 'plate' of wood
that was a little larger than the light colored circle in the picture above.
we could see a ghost of where the missing 'plate' rubbed when the top was swiveled.
worked perfectly ..
so then, luckily, we had two pairs of drop leaf table hinges on hand, and they
were the right size, but the original screw holes didn't line up.
patch the holes, attach the top .. good to go ...
an interesting repair ...
now if we can just find the mate to it, the client would have a nice dining table