Select the campaigns, ad sets, or ads with the checkboxes, click Bulk edits, and use the Pause or Activate buttons in the actions panel. The table updates instantly, and the system applies the change in Meta in the background, then shows a notice with how many items were changed. If any item fails, the notice shows how many, and the data reloads to reflect the actual state. You can also pause or activate a single item with the on/off toggle on its row, without opening the panel.