Hello Richard,
Thank you for your question about bringing back a deleted section. If you have accidentally deleted a section of your page, or made an unwanted edit, you can undo recent changes by clicking the Undo button in the toolbar:
You can also press Ctrl+Z on your keyboard: press and hold the control (Ctrl) key (or the command key on Mac), press Z, and release both keys.
However, if you have saved the page and left the page you will not be able to go back and undo the changes.