No, it's not an oil can or the Tin Man's hat. It's a sausage stuffer! Meat is packed into the larger opening of the tin tube using the big end of this smoothed wooden plunger:
The ground meat is then forced through the tin tube and comes out in long thin lines of sausage. The meat can then be tapered off every few inches to create links.
Sausage was a popular food in Lower East Side butcher shops because it was an economical treat for the customer and an efficient way for the butcher to use many parts of the animal at once. A century ago, butchers would sometimes include the scraps and organs of the animal in the meat.
Tin sausage stuffers with wooden plungers were the most practical way to make sausage before stuffers with cranks were made available. And you can still find antiques like this online for low prices if you ever feel like making dinner the old-fashioned way.
-Posted by Joe Klarl