To clear the downloads list:
Choose Window > Downloads.
In the Downloads window, click Clear.
Safari keeps a list of the items you’ve downloaded. You may want to clear this list to maintain privacy or reduce clutter.
Choose Window > Downloads.
In the Downloads window, click Clear.
To have the downloads list automatically cleared, choose Safari > Preferences, click General, and then choose an option from the “Remove download list items” pop-up menu.