Evaluating Options, RSU's, and Share Based comp

Hello. I'm looking at Palo Alto Networks 10q and they have a section with Option info, RSU info, and then a section called share-based compensation. A couple of questions:

I'm trying to do a treasury method but not sure how to interpret some items. What are options exercisable vs. options vested and expected to vest? Do you handle RSU's the same way as options for the treasury method? At the end they say shared based comp is 510 million, yet the number of options is less than 10,000 so I don't understand how the total share based comp could be so high. (These are Q3 numbers). I'm taking a course on this but the example that they give is very simplistic.