Well, the simplest way that I have found to import photos and vids from the iPad to your Mac is as follows:
1. Connect your iPad to a PC (not Mac)
2. The import Assistant will give you the possibility of importing all the contents.
3. Connect an external hard disk to the PC and copy these files into it.
4. Connect the hard disk to your Mac and move the pic and vid files into your Mac
You can also import pictures via iPhoto.
Connect the device to the Mac with the cable and laucnh iPhoto. Your iPad should appear under the devices heading on the left side of the iPhoto window just like it appears in iTunes. You will be able to import the photos in the camera roll.
This article talks about all of the different ways that you can import your photos to your Mac.