It's a device for making shaved ice. You put icecubes in the top of its head and crank the handle and a razor cuts sheets of ice off into a cup. Then you put syrup on it. It seems to be more popular in Japan than in the US, but you can still find them at most fairs and carnivals.
comment #36101 It's hollow_ataraxia. I dunno. I think Shiro decided they needed to have a birthday party for Saber. They said today is as good a day as any since we don't know her real birthday. Have this shave-ice machine! Saber loev food.
so why would a king be impressed by such a common toy?
Also, remember the time she's from. Toys were very simple back then, and Britain in specific was doing poorly around the time of her reign in Nasuverse.