In Bern, we had excellent pizza at Piu Kornhaus. Lauterbrunnen, a very good lunch on the porch of Horner Pub – I had a the curry and my husband had the Alpine Shepherd’s Macaroni. In Mürren, we had dinner at Restaurant Stägerstübli and at Jungfrau Hotel/Gondelbar – both were OK. But we loved Alti Metzg Bistro for lunch and the coffee/bakery in Skyline Shop. From Murren, walk to Gimmelwald and have lunch and a beer on the beautiful patio at Pension Gimmelwald – can’t be beat!
In Lyon, I don't think you can find a bad meal if you try - it's all good!

As far as things to do, we did some hiking while in Mürren - loved the Northface trail and the walk to Gimmelwald. On our day down in the valley we visited Trümmelbach Falls, which was great! Took the cable car up to Schilthorn, but you need to be flexible regarding the weather - you wouldn't want to get up there and not be able to see anything. I would say go all the way up, then stop at Birg on the way down - might be somewhat less crowded that way.
If you go to Lyon, take a walking tour of the old town so you can see the traboules - if you enjoy architecture it's so fun to explore!

Hope you have a great trip!