You will see tiny bubbles as you mix any epoxy resin, that is just a part of the mixing process. Air bubbles are caused by oxygen that is inevitably whipped into the epoxy as you stir. Do not mix epoxy too quickly or rigorously; this will create additional air bubbles into the mixture before pouring.
The torching process removes them.
After pouring your epoxy, you should be a lot of the bubbles disappear. Be sure to use a torch or heat gun to eliminate the rest of the bubbles on the surface. Using your heat device in an evenly and continuously moving motion to help remove most of the bubbles on the surface. This step is crucial because it not only levels the epoxy and releases small air bubbles, but it will also give it a glass-like look.