Probably the only way to stop it would be to turn photo stream off in Settings>iCloud on your iPad. This will delete all photos in your photo stream album if you do.
If you have poor internet speed in your area, photo stream might not be the best solution for you. You can also import photos to your computer (http://support.apple.com/kb/HT4083), then sync them to your other devices from the Photos tab of your iTunes sync settings. You could also use an app like PhotoSync to transfer them to your other devices using your wifi (without going over the internet).