I would not consider it a major issue but it does happen. If it continues to occur again and again, that could be a different story.
A couple of tips ....
Make sure you keep the battery charged. You don't have to charge it every day, but if it gets low recharge it.
You could also try closing apps once in a while. That can't hurt either. This is how to do it.
Double tap the home button and your recent apps will appear at the bottom. Hold down on any app icon until it begins to wiggle. Then tap the minus sign to quit the app. Close all of the open apps the same way. Then tap the screen. Now restart the iPad.
Hold down on the sleep button until the red slider appears and slide to shut off. Hold down on the sleep button until the Apple logos appears then let go of the button and the iPad will restart. See if that helps.