Our database documentation explains what each Lansweeper table stores and can be searched using your web browser's search function: https://www.lansweeper.com/knowledgebase/accessing-the-lansweeper-database-documentation/
Help desk ticket notes are stored in the htblnotes table. Keep in mind though that the entire HTML of the note is stored in the database, not just the text. The output would not be very readable. To attempt to strip HTML from the notes, you would have to start using advanced SQL scripts or functions, which neither we nor our report builder provides support for, unfortunately.
In regards to attachments: attachment names are stored in the database, but the actual attachments are stored as files on your web server and not in your database. This knowledge base article explains where Lansweeper files are stored: https://www.lansweeper.com/knowledgebase/where-lansweeper-data-reports-and-settings-are-stored/