The Ad List displays all your created ads.
Double clicking on any ad, will take you to the Ad Edit page.
If you right hand click on an ad, you will see the following options:
Duplicate Advert - this allows you to duplicate the ad, you will need to name the new ad and select the publication and date as if it were a new ad.
The tick box on the far left allows you to select multiple ads to move to archive or delete.