Seen lots of old stuff around my great grandpaws farm, nothing like that. Seems the two outside plates hold something and that big more black colored middle part is a knife/shear of some sort operated by that large handle/ratchet mechanism, then twist an outside plate it in to cut another slice? No idea if I'm even close or even if I am close what it would cut?
I'm with QQ, it is a finger eating looking son of a gun...