It's a zip file containing 32 .csv files that each contain a different type of data. poll votes, saved posts and comments, user preferences, comments, chat history, gilded posts, messages, and so forth. It seems likely that you could recreate whatever parts of your account that you wanted using it. Though the saved comments and posts are just the urls of those things, so if they're already deleted or private you'll have to go ask the datahoarders for the details.