Is epoxy scratch resistant?

Yes. The resistance level is determined by which type of epoxy the surface is made of.

For UltraClear bar and table top epoxy:

This epoxy is very resilient, but can still be scratched by sharp or rough edges. Because of its nature, scratches on epoxy are generally unnoticeable. Essentially, you just want to not use the epoxy as a cutting surface. Like with most countertops, you should use a cutting board for things like that.

To get the longest lifespan from your epoxy, make sure you don't place extremely hot items on it, either. Use coasters and placemats to protect it from very hot things.

During the first couple months after the initial curing period, the epoxy with be over 99% cured, but not yet 100%. At 100%, scratch resistance will peak and heat resistance of epoxy will be up to 135°F maximum. Do not treat the epoxy like you would tile. They have different strengths and weaknesses.

Caution: Take care when using products containing a red dye or other colored dyes as they can stain the epoxy. 

For UltraClear deep pour epoxy:

Deep pour epoxy is not meant to be a stand-alone finish for wear surfaces such as table tops or bar tops. For projects that will be used for a wear-surface, it is necessary to apply a topcoat at the end, using either the table top epoxy or an Osmo finish.