You can do that stuff in the engine. A rough idea would be:
- Import your mesh into UE (as a skeletal mesh)
- Make a blueprint from the mesh
- Add two triggers to the left and right pages, for example the lower left corners (to go forward/backward)
- Catch the mouse clicks on the triggers to, well, “trigger” the according page-turning animations
- For the elements on the page, you could use decals (and catch mouse events on them to see if the user clicked on one of them)
- Create some spritesheets and hook them into the decal material if you want to animate the graphic of the decals
That should work 
Cheers,
Michael