Whatever the brightline test for "a lot" is, there's no compelling reason each tab should be consuming about 70MB. Under Chrome, each tab runs in its own process, which is certainly a contributing factor. I appreciate this is for stability and security, but it's not the best solution for the problem and has some serious drawbacks, i.e. horrible memory usage.
As I said in another reply to one of your comments, I don't think 70MB is a lot per tab. I'm fairly certain that if you run Firefox 2 for instance it'll use close to that amount for one tab.
