How was this effect achieved?
Faking a finger being cut off is pretty easy. First, they can just use a rubber hand for the closeup with the actual cutting. If the actor is wearing something with sleeves, their real hand is up the sleeve holding the rubber hand.
If the script needs the rest of the fingers to be moving around, you can make a glove with something fingerlike and some fake blood in one finger of the glove, and the actor can curl their real finger down onto the palm of their hand inside the glove. Then the fake finger can be cut. You can put tubes for fake blood in the palm of the glove.
Generally a scene like this will be done several times from different distances, with different amounts of makeup and prosthetics each time. From 20 feet away you just need a tube on the table under the person's hand that will spray or ooze blood. You might also need another glove later to make the person's hand look like they're missing a finger.