: They also made Lembas which was their food for long journey. Galadriel gave some to Sam and Frodo and probably kept them going through Mordor.

To expand on the lembas thing. They were made with a special corn by that was from Valinor. When the corn was given to the Eldar, it was warned that they should not give it to mortals, at least not much of it. If a mortal has a sizable quantity it makes them yearn to go to Valinor, something unheard of, at least until the end of the Third Age when Frodo, Sam, Bilbo, and Gimli all at least made it to Tol Eressëa.