Workspaces are where your storage is accounted for and where you upload files to.
Backup and Restore function in the Studio One menu will open the window to upload / download your files to / from your cloud storage.
At the bottom of that screen is a link to "Manage Backups" which can also be accessed if you want to see in total what you've uploaded, from your Sphere home screen, click on Account, then Storage.
There you can select what you want to download individually or all at one and/or delete.