Everything ending in .txt is a text file, that you can read in any app that can read text files. (Tap the file, then choose an app from the list.)
They appear to be xml files (xml is a particular format of straight text) that probably belong to some app. If you delete them and the app needs them, it may complain. Or they may just be orphan files, not belonging to anything. There's no way to tell from just the short piece that we can see.