I have checked PRPC 6.1 sp2 and Pega 7.1.7 and found out that the height of ootb summary view is defined in .MainDiv class of query_wizard.css file.
By default, it is set to 300px. See below snapshot. You can increase this number to have a big screen.
For your summary view, based on the snapshot you posted, I suspect that you have your own css file to control the height. If you can find it (e.g. using Developer Tools, F12 on IE browser), you can modify the height to have a big summary view screen.