If I’m playing in a televised poker tournament do I have to show my cards to the "pocket cam"?

Could I block it with my hand or some kind of item?

I justed started watching world series of poker and noticed players like Raymer put a card protector on there cards and put on there sunglasses right after that. What is the point of the card protector?

I want to practice dealing on a real casino poker table, what are the measurments of the tables? Also, what kind of cards do they use? Bridge sized?