Thanks ghiottone for mentioning my blog article!
Roseolson, another -simpler- lunch option is Trattoria degli Umbri. This one is closed on Thursday though. whatever place you take make sure to book an go really early.
During the calendimaggio you should also be able to eat some porchetta at the "taverne". Taverne are a medieval storage rooms which are transformed into snack places throughout the festival. Nothing fancy but if you are in a hurry you grab your sandwich and your cup of wine and off you go.
The Calendimaggio is a fantastic event, here you can find some extensive video
Calendimaggio part 1
Calendimaggio sbandieratori part 2
Calendimaggio medieval life part 3
Calendimaggio spring dances
Thank you! Thank you! We are going to be there on Friday. We tour the basilica in the morning, have a mass and then have just about two hours before going to the festival. I am going to try and book a table at the Trattoria. I might ask my hotel in Rome to call ahead for me now. I am so excited to be there for such a neat event. You are wonderful to post all of those links for me.
While in Assisi last week, I had lunch at Pallotta based on the recommendation made by madonnadelpiatto on this post: http://chowhound.chow.com/topics/698340, which also contains several other suggestions for dining in Assisi.
It was quite good, though as we ate only primi, I can't comment on the secondi. Also, several seasonal specialties are currently on offer (i.a., asparagus).
http://www.pallottaassisi.it/new/int/... (note that they are closed on Tuesdays).