The sqlite files with the “backup” prefix can be deleted. They are created when upgrading to a newer version of Duplicati that introduces a database schema change. They are useful for a short time in case you need to roll back to the previous version for some reason. Once you’ve used the new version for a while just delete them.
There was some discussion last year about Duplicati automatically deleting these, but I don’t think it’s high priority from a development point of view.
The LIRNGNGCCS.sqlite file looks like it hasn’t been touched since January. Do you have a backup job still defined that you haven’t run since then? If it’s from an old backup job that you no longer need or care about, you can delete that file too.
The VHVRJIQYOT.sqlite file may be able to shrink if you run the vacuum command. You can enable the --auto-vacuum option if you want Duplicati to do this after each backup.