@stokergYes, I was the user that reported you this file size problem
I hope you can find a solution very soon because working on big photo books gets really frustrating... Not only that the file size is huge is a a problem, even the speed of the App gets slower and slower over time...
@MikeTO you can temporary get the file size small by first embedding all pictures and then linking all pictures again in the resource manager. But you have to do this step before every saving action because the file size gets up again with the next saving action. In my case the file size gets up to several GB because of that many pictures...