Using a Windows tablet as an e-reader is not something I would recommend but there are some applications that can make it work. Below is a list of recommended applications:
E-Books: The choices are limited for e-book reading applications, in comparison to Android. Book Bazaar and Frida being two good options. Amazon's Kindle is poorly supported and the only viable option is to download the poor PC version of the application. Oddly, Amazon supports an Audible application in the Windows Store. There are also OverDrive and Kobo applications that are downloadable from the Windows Store.
PDF documents: Adobe Reader Touch, XODO PDF Reader & Editor and Foxit Mobile PDF are all good choices that allow the user to annotate and edit PDF documents.
Note taking: OneNote is the better option as it is fully integrated into the Windows eco-system and there are no subscriptions cost restrictions similar to Evernote.
Cloud storage: Similar to OneNote the choice would be to use Window's native OneDrive for cloud storage to sync reading between devices. There is also a Dropbox application in the Windows Store.