Can I make a screen grab on iPad?

There is indeed. Quickly tap the Home button and the On/Off button at the same time. The resultant picture will be saved to the Camera Roll.

Press Sleep/Wake button and the Home button simultaneously.

http://www.digitaltrends.com/mobile/how-to-take-a-screenshot-ipad/

@Fisher1950

View the link below and it will show how to perform screen grab. Even though it say iPhone, it still works the same exact way. Cheers!

Take a screenshot on your iPhone - Apple Support