This is an heirloom technology so wood shaping. Used to make tool handles, chair legs, paddles, etc.
There is nothing new about the shave horse, it's been around for a long time.
Here is a link to a google image search https://www.google.com/search?q=shave+horse&tbm=isch
There are various ways to clamp the workpiece and some variations on the location of the pivot point...
and you will want probably both a draw knife (removes more material) and a spoke shave (removes less material)