There is quite an active book builder community for eSword and TheWord that has put together thousands of books, mostly in the public domain, for use in these Bible programs. See links in the attached file for some download sources.
Using a free program called database2rtf you can convert these modules to RTF format. The attached Word macro file can take that file and prepare it for use as a Logos Personal Book. Instructions and links are inside the attachment. Resulting files might still need a lot of manual work (partly depending on the quality of the input file).
This will not convert Bible modules, use Bible Multi Converter instead: https://github.com/schierlm/BibleMultiConverter/releases
Please let me know if you find any problems with the macro and I will try to take care of them (as time permits).