Hi. If you really do. It want these databases to be available anymore you can delete them from the database folder located in your Board directory. Just delete the complete folder ending with .hbmp. I suggest to keep a backup of the database you are deleting.If I remember correctly there is also an option to delete a database from the burger Menue in the datamodel section of the web client.
BR
Sebastian
Ok. One more thing: make sure to stop the board engine before performing any actions in the database folder.
BRSebastian