Yes, the majority of Mexicans have at least some degree of Native American ancestry. It could be from a number of various tribes, like the famed Aztecs or Mayans as well as lesser known groups like the Zapotec, Olmec, Toltec, etc.

That's interestingly a high Italy/Greece score btw. If you don't have any direct Italian/Greek ancestors, maybe you have Spanish/Iberian ancestors who were heavily descended from Roman colonists or something since genetic ties between Spain and Italy have always been pretty strong (hence linguistic/religious similarities and what not).