Yes, you can! Next to each Folder and Activity, you will see a small checkbox. Once you select at least one checkbox, the Activity Toolbar will appear.

Click the trashcan icon to delete your selected Activities. You will be prompted to confirm the deletion. It's important to note that you cannot delete folders that contain Activities. You will first have to delete those Activities.

If you move items, click the "Move Selected" icon, then choose the folder where you wish the items to reside. Confirm the move and the items will be moved for you