Mar 3, 2016 - 6:19 AM
Whether you need a SIM card depends on how much you prefer to do online. If it's really just for booking restaurants I would not buy a card. You can call them or use the (probably more expensive) data package of your own provider for a minute. Restaurants won't be busy, apart from very popular places or if there are events nearby.
If you want to receive e-mails, check train schedules, the weather, etc., a SIM card might be convenient and save money. Please see myswissalps.com/ simcard for some good options.