I am not sure why Microsoft made the Ribbon Tabs in Office 2013 All Caps, when Win8 File Explorer and the Apps use Initial Caps. Perhaps they thought it would draw the eye and so to more easily find the tab you are looking for.
Whatever the reason, apparently there are quite a few users out there that find them to be distracting and annoying.
Follow the steps below to change the All Caps tabs to Initial Caps:
- Select any tab on your Ribbon and Right-click .
- Select Customize the Ribbon.
- On the right-hand side, click Rename and give your tab any name you like.
If you would like to keep the name already assigned to that tab by default (which I did), simply rename it with a space at the beginning or end of the name, or modify it in some other way (i.e., _Home_).
There is one caveat and that is that you cannot rename it FILE.