The abs.txt, bib.txt, as well as some similar files are required for all saturn games -- the "txt" files only need to exist, the contents really don't matter.
Multibooting a disc would be extremely difficult for multiple commercial games, as you would need to likely create a bootloader program as well as modify the commercial games as well -- I'm not sure this is even possible.
You'd have better luck just laying out the very small amount of cash CDRs require.