Loads of Legumes
Dried legumes, namely lentils and beans, were a significant part of a sailor's diet. Columbus would have eaten plenty of lentil stew, boiled beans and chickpeas seasoned with what the ship had handy -- basically, salt.
What Christopher Columbus and his crew probably did not eat, or at least didn't eat much of, was fresh meat. That, too, would have been salted.
For a commemorative meal…
Consider lentil soup, hummus or baked beans (with brown sugar, since Columbus did have sugar on board).