Hello,
Under the Dashboard > Theme Settings > Single Product > Tabs > there are 3 Additional Tabs which works globally for all Products: https://snipboard.io/Uc3MER.jpg
These Tabs accept simple Text or HTML Block whichever you like.
Secondly, under the Product Edit area you will find two specific Tabs to add: https://snipboard.io/1mizWH.jpg
In these specific Tabs you can add .PDF or .WORD file if you want using the Add Media option there. We have shown an example in the above image related to this. We have added a PDF file in the Tab and it is accepted easily due to Rich Text Editor availability.
So, you can use this specific Tab feature to add .PDF or .WORD files under Tab.
Hope this helps !
Best Regards