A said ^ if it is chipped or TSOP-ed you should be able to run Hexen or whatever burned to DVD-R and install an alternative dash, applications, emulators etc.
All the stuff you're seeing in those gamesaves are stored data/user settings for the previously owner's dash(es) and applications. You can't do anything with them they're just an indication that the Xbox has been modded at some stage. That doesn't mean it is now though - the chip could have been removed or, if sodtmodded, restored to retail.
What I have noticed is that in your picture you have what appears to be a loose copy of Splinter Cell. That may or may not be significant because Xboxes were usually bundled with it but........... :-
If there's also an original Splinter Cell gamesave with some evidence that it's not an ordinary save eg. a SID or Linux main logo rather than just the game's logo. That would suggest a softmod although sensible chipped Xbox owners may also have put it in place as a safety net. There would also need to be a separate installer gamesave to be able to make use of it.