In order to properly delete items, you'll need to be a workspace admin. 

Typically, the primary account contact will have admin control and can delete any item they please. If you're unsure who's the admin, here's how to determine who has admin controls. 


Click on the wrench looking settings button on your Activity home screen and choose "Manage Members"

You'll see the admin(s) member under the "Role" column:

This is who will be able to delete items or make other users an admin so THEY can delete items too. 

To delete an item from the App View, make sure you're viewing the table format:

Then, you can select which items you'd like to delete and click the little trash can in the top right corner:

You can also delete items by clicking on the item itself, choosing the "Actions" dropdown and selecting "Delete"