If you usually take photos or record videos with an iOS device, you might have learned that you can’t get photos or videos back into the Camera Roll again, once you have deleted them after an iPhoto import. Because the Camera Roll is one-way street. However fortunately, I have a viable way to help you recovery images or videos on iPad Camera Roll. The way is to use the Camera Connector Kit.
At the first place, you might want to sync these media files on your iPad Camera Roll to iTunes or iPhoto for management or preservation. But sometimes, you just want to put these media files back onto your iPad so that you can share them with your family or friends better. At this time, you can follow the below method.
Before doing this, make sure your iPad runs iOS 4.3 or later, no matter what model it is. Then you need an Apple iPad Camera Connection Kit and a SD card or some type of USB 2.0-based digital camera. The kit includes adapters for both purposes.

Now, the tick is below: The iPad which is plugged into the Camera Connection Kit can recognize any compatible media you copy to a properly-formatted storage device containing a “DCIM” (short for “Digital Camera IMages”) folder.
And the steps are as follows:
1. Mount the camera media on Mac simply, browse to the DCIM folder via the “Finder”, copy your photos (.jpg) or videos (.mov) into it.

2. Eject the camera or SD card from your Mac, connect with the Camera Connector Kit adapter, and then plug it into your iPad. At this moment, the Photo app will run automatically. And then you’ll see a window which displays the just-copied media.
3. Choose “Import All” option to get everything (including photos and videos) back into your Camera Roll. When all media files are imported perfectly, you can unplug the Camera Connector Kit.
Now, you’ll find your media files have amazingly been back into your Camera Roll again, as shown below:

Sadly, this method is only available for iPad, for the Camera Connector Kit is compatible with iPhone and iPod touch etc.
You can also see:
iPad 3 Rumors: What You Need to Know
Before You Buy: 12 Things Need to Know about the iPad
iPad 3 Not Coming This Year?
How to Reformat Your Apple iPad
Convert video to iPad, iPod, and iPhone compatible formats
Transfer songs from iPod, iPod touch to iPad with Mac