That's a nail puller with multiple slots. I briefly worked in a shoe factory (boy, was I glad when the foreman told me he was letting me go!), running the last stapler, which sent two nails through the sewed upper into the wooden foot-shaped form, the last, around which the shoe would be made. I used an identical tool to remove nails that misfired, and the folks down the line used them to pull my nails when it was time.