Usage problem with my iPad Air
First, you should update your iPad to the latest iOS system and then if it still takes up you much space, I guess maybe there is much junk files or "other" storage on your iPad Air. You should know what is the Other storage clearly firstly. There are just too many things that require physical storage. That's why Apple chose to lump a lot of things into the "Other" category. Also you can refer to this thread who has the similar situation with you. Hope it's helpful to you. https://www.reddit.com/r/iphone/comments/3elqfe/iphone_6_says_storage_almost_fullexcept_its_not/