Depending on the camera, you could also transfer via Wi-Fi. If all else fails, you can use a computer to facilitate it. Plug both into the computer's USB ports, then use the file browser to copy and paste the photo from the camera to the tablet.
Don't cut and paste, or you risk losing the files if the transfer corrupts. A cut and paste deletes the original immediately, so doing a copy leaves it intact. As another side note, it's often recommended in photography to not delete the files from the camera's SD card. If you are done with everything, use the camera to reformat the card to prevent corrupting it. SD cards (both regular and micro-) are not designed to handle a lot of write and deletes, so a quick reformat uses less write cycles by only deleting the file markers and rewriting over the old data as needed.