My suggestion for Cabo is a place called the Trailer Park. (No, it's not actually a "trailer park") they have the mose unvbelievalbe food you can ever imagine. I was there last year and went to this restaurant twice my my husband. If you can try the deep fried red snapper, it's huge and was the best fish I have ever had in my life.
Yes, there are other places on the beach, The Office, etc. But if you truly want a great lunch, I highly reccomend this place. Just ask a taxi driver to take you there, they know exactly where to go.