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A month ago I set up roughly a hundred Asus Nexus 7's for Android for Education management, but it was for five 1:1 K-1 classrooms, and of course my models aren't the same as yours, so YMMV. /u/jasmadic's link is basically what you're looking for, but maybe I can help clarify. This page makes me assume your tablets are NFC-capable, which is key to this method. But anyways, here's what I would do:
Then, all you have to do is wait for the app to say "Ready to bump" next to each tablet, grab that tablet, make sure it's awake, and bump it. Wait a few seconds or minutes until it says the next one's ready to bump, then bump that one, on and down the line. I might also encourage labeling each tablet with its intended assigned username (or something similar) first.
All this being said, it can still be a bit painful. I'd say a quarter of mine didn't start the actual enrollment correctly and had to be normally (manually) activated, then had to set them to wipe, which takes a good 5-10 minutes per device. If the admin app doesn't see that they failed, or doesn't give you the chance to retry, you have to set them aside and start fresh with a new Sheet with just those missed tablet accounts. Also, I had a handful that successfully enrolled, but for whatever reason wouldn't join the wireless network, and because I'd set the enrolled devices not to be able to change wireless networks, I had to hard wipe them using that link in the first step (probably a good reason not to prohibit them from changing SSIDs right away).
After everything's rolling, you can set up teachers with the ability to push apps to either the generic user groups or to individual generic accounts through Google Play for Education, the details of which are here. It also isn't a perfect system yet, but once it gets working, it becomes a lifesaver. In my experience, it beats the hell out of any MDM iPad management I've seen, etc.
I'm still fairly new to Android device management myself, so I'd love to hear some of the more experienced folks offer their own suggestions for better ways to do this, but darned if I've been able to find anything so far. Good luck!
EDIT: Added a few points of clarification and tidied up, and again, and again, and again.