Q: how to completely remove office from ipad

If you access your iTunes from a computer I know you can delete it from the iTunes on your computer and you'll stop getting updates for it.  I"m not sure if you can do that on your iPad or from  your iPad.

In iTunes on your computer, you can hide them - Hide and unhide purchases in the Mac App Store - Apple Support

theoretically, you can do this in iOS as well, but it currently does not work (the hide resets to show when you reopen the App Store) but will likely get fixed with iOS 8.4 soon.

If you removed them from your iPhone, you should not get updates.  Hidden or not, is irrelevant to update notices.

What exactly is th App Store saying? A screenshot may help us better understand.