A family of Microsoft word processing software products for creating web, email, and print documents.
This fix has worked for me and resolved almost all of the lag issues.
Go to Settings > Word > Reset Word > select the option to Clear All Documents. The next time you open Word it will clear out the old document cache and speed it up significantly. Beware though, make sure any recent changes you made have been successfully saved and you can see the updates in the saved location before clearing the documents. If they haven't been successfully saved before you do that the most recent updates could be lost.
Bravo to Microsoft for actually taking care of their customers and making this known to everyone! (Sarcasm)