In this app, you can take pictures of the meals you eat (and the people with whom you eat them), add comments and restaurant information, and then automatically sync this information into the Evernote mothership, its synchronized notebook.
It's a pretty lightweight app, but it is kind of fun, and it could be useful, I suppose, if you were really obsessive about recording what you ate. It could also eventually be good for recording things like wines you like, but Food doesn't yet collect enough structured data to be a real foodie's app.
Food is not an inherently social app, nor is it a rating system like Oink. You can share your items out on Twitter of Facebook, but the app is designed primarily to help you remember what you ate, or how to prepare it, or to document important meals you had with friends or associates.
I'd like to see better integration with Evernote (like the capability to edit Food notes inside that app) and other services (Yelp, Oink, Epicurious, etc.). While Hello's focus on building a private narrative of the people you meet makes sense, Food feels limited by being a mostly private service.