Murano's is a pay restaurant - $30 per person which includes the tip. Suggest you book it as soon as you board as it only holds about 62 people and they stagger the reservation times. It's the only pay restaurant onboard. Largest table is for 6 (and they have two of them); smallest is for 2 and I'm not sure how many there are, but not many.
Can't help you with the excursions - sorry, didn't take any ... been there done that!