ST Luke's Leftovers

When Rey is maneuvering through the ruins trying to find Luke, she comes across a small box lying on the ground at one point.

My first thought was that it was a leftover meal left behind by Luke, kind of like those little boxes of food he used on Dagobah in Empire that Yoda rummaged through.

Maybe Luke left it on purpose as a sort of bread crumb trail to help Rey find him?

What do you guys think it is? Seems insignificant but... it's a new Star wars and half the fun is over analyzing everything!