If there are past events you wish to remove from the picklist for the main Events or Event Attendance grid you can Archive them. Archive will take place on the Event Pages grid by going to Workspace>Events>Event Pages. Scrolling the Event Pages Grid to the far right will display the Archive File Box icon.
By default, only Events which have not been Archived will be displayed on the grid. A filled in file box will identify an Event which has not been archived. To Archive an event, click on the filled in Archive File Box icon. A new window will open asking you to verify the Archiving by typing in “YES” and clicking “OK”.
To see all events (archived and unarchived) check the box at the top right corner of the grid to “Show Archived Events.” Any events with a file box that is just an outline is an Archived event. You can unarchive the event by clicking on the Archive File Box icon next to the Trashcan icon.