Early June: Do we need dining reservations in Murren?

Definitely don't need them for lunch and they'd look at you like you had 3 heads if you tried. Dinner it doesn't hurt to do your most important ones since you have a larger group, but you don't have to do it months or even weeks in advance.

As a courtesy to the restaurant I would suggest definitely making dinner reservations since you are a larger group. You may be able to make a reservation at lunchtime even for that evening.

I strongly suggest you make bookings, at least a few days in advance if you want a popular spot. I was in Brienz last May and all the good restaurants were usually full for dinner, even on weekdays.

Wow. Surprised to see these posts. I've been to Murren twice recently, both times in June, and have never made a reservation. Depends how stuck you are on a particular location, I guess.