Law 45A. Play of Card from a Hand Each player except dummy plays a card by detaching it from his hand and facing it on the table immediately before him.
I am trying to get a definitive response to the meaning of facing it on the table. Logic, and normal practice, indicates to me that the card should be placed on the table face up. In practice some players do not place the card on the table but keep it in their hands, still "faced" as such but some also have a tendency to move it slightly during the play which can be off putting. In comparison Law 41D is very specific about laying down dummy's hand.