Thank you for the suggestion, Sue ... I guess the shape could have been copied, but would you use glass to make such an item? Also, the meat tenderisers I'm familiar with, have a "spiky" surface (base) - my item is polished flat, and shows no sign of wear at all (so it at least would never have been used).
I guess the next question cannot be answered before more is known about the purpose: where / by whom was it made?