As long as the card isn't encoded to the specific device you should be able to use the file manager app on it to move files to the device itself from the card. If you don't have a file manager app you can find them on the play store. Most of them, however, will not let you move a lot of files at once.
Now another option, should you want to move many files at once, would be to connect the device to a computer, via USB cord, while the card is in it still and then use the computer to move the files from the card to the tablet. I would suggest also backing them up to an empty folder on the computer. Backups are always a good idea.