Do you mean 18th century, or the 1800s? It doesn't look like an 18th c piece.
Am I right in guessing that the arm is attached to a screw, and that as the arm turns one way then the screw lifts or lowers the platform?
I have no idea, but I'm wondering what might have come in a tube shape that needed cutting....??
I have absolutely no idea why, but for some reason I'm thinking of chewing tobacco
But probably light years out.