'Bendy Bones' are a good fit for this.
Start with a suitably sub-divided plane :
Create an armature (single bone) and position it along one edge :
In Edit mode (Tab) duplicate the bone and position on the opposite edge :
Change the armature Display to 'B-Bone' :
While still in Edit mode, select each bone in turn and change the Bone properties Bendy Bone Segments to a suitably high number for your mesh level of detail (eg, 10 - more segments make for a smoother bend) :
Now swap back to Object mode and parent the armature to the plane (select the plane, Shift-select the armature, Ctrl+P, Armature Deform with Automatic Weights).
Now, bending the bone (by changing the Curve XY Offsets) will bend the page.