It depends on the places rules. You can't take them off of the table. What some dealers let people do is pick them up to look at them as long as the cards don't go past the rail, or other people see them, (hard to explain) they won't complain. For example you can't pull the cards toward you, take them off the table, and hold them up to your chest while you look at them. They are supposed to remain on the table and in plain view of everyone at the table.