|All microSD cards, of whatever capacity, are the same size and shape exactly.|
Otherwise they would not have the same name - microSD.
Putting it in the wrong way up will cause it to stop as though it's blocked by something. I don't need knowledge of that particular tablet to know that because the same thing will happen on all devices with a memory card slot if you put the card in the wrong way up. I can't think of any other reason why it won't go in all the way.
Take it back to the shop if you think it's faulty. If you bought it online, go to their website and see if they have user reviews for that product.