It is a sugar cutter, as the wealthy household would buy their sugar in large cone-shaped hard blocks. Think of how sugar can clog up at the bottom of a sugar basin - well that kind of thing but big enough to stand on a table-top.To use it, you broke sections off with the cutters then ground it up. Hence packets of 'ground sugar' nowadays.
mosaic, I remember my mother buying salt in solid blocks like that - we chipped a bit off when we needed it. I remember wet days when I was about six, carving statues in the salt block!
Looks like something Mrs O has got lined up for Tony & Mopedboy ...
... I remember salt in blocks boxy, but can't remember the brand name - don't think it was Saxa and Cerebos was the one which made a big point that it was 'free running' - any ideas?
It's for cutting sugar. The handle is raised to open it up, and brought down to cut the sugar.A kitchen in a grand house, or a grocer's shop would have one. It was only in the last century that anyone thought to sell sugar, salt, tobacco and other dry goods in packets marked by weight.