Educational tablet mass-customization
As the tablets are all identical, and run Android >= 4.0, the following approach could be taken – provided all devices should be configured identically:


Configure one device the way you want to have them all
Use adb backup to create a backup of this tablet (see our adb tag-wiki for a starting point if you didn't use ADB before)
Use adb restore to restore the created backup of the first device to all other devices


This should transfer all apps and settings from the first, manually configured device to all the others (including homescreen settings). You can play with parameters to adb backup to speed up the restore process, e.g. by specifying to only include the apps you added/modified, e.g.

adb backup -apk -shared -f backup_customized.ab com.package1 com.package2 …


(replace com.package1 com.package2 … with a list of packages you want to include). Skip -shared if you don't need to clone SDCard contents (you also could copy those separately, which even might be faster).