You can mass edit multiple files at the same time. You can select all files in a space, or specific ones, and then move to folder, add tags, favorite, or delete.
Bulk edit is available from within a space on the Tasks and Files tab. When you click into the Files tab, click the pencil icon in the upper right under the plus (+) icon to access the bulk edit options. You can then click the checkbox at the top at the left to select all files or go through the list and individually select the files you want to affect. Once the files are selected, click the icon in the upper right to perform the action you are interested in. Click the folder icon to move the files to a specific folder, click the tag icon to add a tag or multiple tags to all the items, click the star to favorite all the selected files, and click the trash icon if you want to delete all the chosen items. You will see a notification at the top of the page after the action completes.