I found some .tdb files on my laptop and now I'm interested in how to open them (on Linux).
It depends…
There are several formats that usually use the extension tdb: https://fileinfo.com/extension/tdb (and maybe even more).
The file is located in the directory: / var / lib / samba / private and is called passdb.tdb.
You can edit them with pdbedit from the Samba package. The format is Trivial Database and more can be found here: https://tdb.samba.org
In this case, it is probably a database of the type "Trivial Database".
See also: https://www.samba.org/samba/docs/3.2/man-html/tdbtool.8.html