I would buckle down and study. This is your last opportunity to have a free week with no other responsibilities without having the biggest exam of your life looming directly over your head. Its also a great chance to review some of those Step 1 topics you haven't seen in almost 2 years that will be on the exam! And you can bet your bottom dollar that your classmates and many of those across the country (your competition) will be using this time wisely (at least the smart ones) while your wasting your time lounging on a beach getting sunburnt.
I spent my spring break before step 1 going over the biochem, microbio, and pharm sections of First Aid. I knew that I had not seen biochem or micro in a long time and needed the chance to start learning it again, square one. I knew that after school ended I would need to devote the majority of my time to path and physio so a head start with some of the other topics was important to me.