It is possible that there’s an app on your iPad that is hogging more memory than you think. Sure, you glanced at the size of the base app before you downloaded it. But certain apps, including Facebook and Google Chrome, are notorious for taking up more memory than advertised. This is because of the certain documents and data that are cached when you are using the app. In other words, certain apps can actually increase in size the more you use them. Luckily, there is an easy way to detect these apps. First, go to Settings -> General -> Usage. Now select an app. You will be taken to a page that will display the app’s base size, and the amount of additional space that is being occupied by the app. There is even a conveniently placed “Delete app” button if you decide to smite an offender.
Have fun with your iPad!