Try using binwalk, file(1) or strings(1) to get some information about the contents of the files ... try searching found strings on Google, etc. Good luck!

--- Edit:

Those four files are really small and I can't see any person's names in them when just opening them as plaintext files, but LINEN contains some instructions for solving math systems of equations: "sistem dveh linearnih enačb z dvema neznankama. Možne rešitve". Other files seem like a listing for a music album (MARLEY: 01. No woman no cry) and possibly lyrics or something in BEATLES (eight days a week she loves you, ... Maybe something for a karaoke program). KASETA is also really short and contains no text - maybe some chiptone music, but that's just a silly guess.

To correct myself: binwalk, file and strings do not help you here. It's not even ASCII text.