I would say it is actually pretty typical. We had lunch as early as 10:15 in elementary school. Here is our current schedule:
Middle school - earliest lunch is 10:40am, latest starts at 12:50pm. School is 7:45am-3:00pm
High School - earliest lunch is 11:00am, latest is 12:55pm, School is 7:50am -3:05pm
As to why the early times, I would think that would be obvious. They can only serve a limited number of kids lunch at one time. Divide the number of students by that and you have to have a certain number of lunch periods, so to fit them all in, they need to start early and end late. I am actually impressed that our HS can fit 5000 students through only 4 lunch periods (they have three cafeterias).
Every time we have had the earliest or latest lunch, the teachers tell the kids to bring a snack for morning or afternoon. The late lunches are actually harder for us - leaving at 7am and not eating until almost 1pm is tougher than a light breakfast and lunch at 10:40am.
Mama to three boys ('03, '05, '07)