Of course on your private guided shore excursion you'll have time set out for a delicious Greek lunch. In addition to being healthy, the meal represents a time for friendship and this time is indeed an incredibly important ritual if not actually the most important one found in the Greek culture.
Your licensed guide, being of Greek origin, will have extensive knowledge of the various choices/names and the history. FYI: the first cookbook came from Greece.
So enjoy your tasty, healthy blend of the Mediterranean diet, and good company.