I just gave it a test run and it looks like I can write out every editing feature Word has to offer:
- Enlarge / Reduce text size
- Red / Yellow / Green text
- Red / Yellow / Green highlight
So if you want to do things like add another row to a table, make a column larger or even basic stuff like indent text, add bullet points, use another colour like blue, etc., well, you'll need to find an alternative Office app.
Windows 7.5 and 8.1 phones have the same above feature list in Word.
Edit: Going by user reviews on the Play store, the iPad version offers much better edit functionality such as shown in the screenshots of the Office Mobile page. On an Android tablet, the editing features are also limited to the tiny selection above.