Well, my experience has taught me that it's a quirky process.
Anyway, I own a Nikon D7000 which has two SD card slots. I have it setup with an SDHC and an SDXC card. For some reason it works if both cards are present, but not if only one card is installed on the camera. The cards also need a fair amount of free space; Tab wouldn't recognize the camera if either card only has 10 or less shots left.
Once the camera is plugged in, it can take a while, depending on how many shots are on it. My record is 35 minutes. If the Tab's screen goes to sleep then I have to start over, so I tap the screen every once in a while as I wait for the photos to be available.
I also own a Canon Powershot S95 but I haven't figured out whatever quirk it has for the Tab to recognize it...
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