Thank you for writing.
Typically, MaxSize and MinSize properties will fix the size, however, they will not take effect in this case. By default, the items of all RadPageViewPages have the same size (you are be change the sizing mode using the ItemSizeMode
property). In this sense, if one of the images you have applied is slightly bigger than the rest, all items will be stretched to match the highest item. So, before everything else, check the size of your images and make sure they do not have a transparent stripe which makes them bigger than they appear to be.
Additionally, the ControlDefault theme applies 7 pixels padding to the top and the bottom of the PageView item. To remove the padding use the following approach:
Padding(4, 0, 4, 0)
I hope my answer helps. Let me know if you need further assistance.
the Telerik team