Surface pro issues with large word doc crashing

Hi all, I need to produce large docs including 800 photos ( sometimes up to 400 pages, 78MB) on a surface pro using a word template but I get to about 80 photos , press save and its freezes or is stuck and I cant continue to use it to finish the work, I have to use a regular camera then upload all the photos to the document on the desktop and label each pic, very tedious and time consuming !! So how can I use the tablet to complete the whole document with the above occurring? Thanks