It shouldn't really be a problem unless you're going from TSH/KTH to ABB or something like that, in which case you should speedwalk. I had time to stop and get food or go to the washroom between most of my classes, especially if one of them was in MDCL
If your second class is full (and you have to rush to get seats) you can either get someone to save seats for you, or leave your first class early--just sit on an aisle. There are also short cuts through buildings that can save you lots of time! 10mins is more than enough time to get to most classes, so don't worry about putting classes back-to-back like that