You can copy/move multiple ebook files at once using the inbuilt File Manager. To copy/move multiple books:
1. Select the books for which you want to copy/move files
2. Open Books -> Files Manager
3. Select the destination folder
4. Set the options (see below)
5. Check the result preview in the New Path column (if it's different from the Old Path, it will be highlighted in green)
6. Start the Copy/Move process
Copy/Move options
- Include book covers - will copy/move book covers to the same destination folder
- Overwrite files - will overwrite files, if they already exist in the destination folder
- Update path - if selected, the file paths in the database will be automatically updated
- Include book folders - will copy/move book files with lowest-level folders