I think its a multi-purpose grater. Cheese, tomato coulis, bread crumbs, what have you. it may be one of those "jack of all trades, master of none" gadgets.
ETA, on our way home from the country, we pass a kitten rescue facility with fabulous thrift shop. So several times a month, we cull such oddments from both town and weekend accumulations. Good cause and occasional relief in cupboard space. But we seem to "leave one, buy one" from their always fascinating stock.