Please tell me what this kitchen tool is called and its use, specifically
Looks like a butter curler to me.


  A butter curler is a kitchen tool designed to produce decorative butter shapes for use in food decoration. It can also be used to make chocolate and wax shavings. In typical use, the material to be cut is chilled slightly while the curler is dipped into hot water to ease the cutting.  


Here's an example of a more modern one and the results of using it: