For each file, you have the following options:
Edit: Modify the file content.
Remove: Delete the file.
To Default: This action relocates the file to the default package. When files are imported, the original folder structure in your workbench is retained. If you wish to organize files into a specific package or folder, you'll need to do so within the workbench itself; creating a folder on this page is not possible.
To Main: This will move the file to the Driver file section.
To Solution: This will transfer the file to the Solution file section.