A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
I have an surface pro 4 I7 16 Gig internal RAM.
Same problem: slower, slow build up of the screen
In office 2010 no problem with performance. filesize: 25Mb
Also thinking to reinstall office 2010.
Your hardware specifications are much more than adequate to run Office. The problem you are seeing is a bad interaction between the part of Word that "draws" Word on the screen and some undefined part of Windows.
The problem first showed up in Word 2013 (I also saw it in Excel 2013). At that time the Word team had completely replaced that part, "subsystem", of Word with a "new & improved" version. Since then MS has released a number of fixes for very specific situations.
If you read through the question you'll see there are a number of suggestions that have worked for other people. The most common suggestion is to switch the current "Hardware Acceleration" setting(s) (Either in Word and/or Windows).