Using the same ad unit code more than once should be fine – if there is enough valuable content.
I’m not sure about “multiple”, and maybe “ten” sounds a bit too much.
Advertising and other paid promotional material added to your pages should not exceed your content. Furthermore, the content you provide should add value and be the focal point for users visiting your page. For this reason, we may limit or disable ad serving on pages with little to no value and/or excessive advertising until changes are made.
Ad placement policies > Valuable inventoryhttps://support.google.com/adsense/answer/1346295?hl=en#Ad_limit_per_page