I was wondering if a Nexus 7 would be a good choice? Had one a couple years ago, but sold it. It was a great tablet. See them used now for about 50 EUR. Question will be the state of the battery of course...?
I've heard the Nexus 7 2013 works well with the Mavic.
Almost bought one myself before I discovered the Huawei T3.
It's a bit longer than the T3 so not sure how well it'll fit in the RC arms. You might need a mount for it.