If RAM usage bothers you I suggest using other browsers.
Notice I didn't say CPU-hog, IE is probably worse in that respect.
I'm regularly watching in my task manager my Memory Usage. 3-4 tabs in Chrome (Yahoo Mail, Gmail, Calendar, CNET) are 6-7 processes (Chrome.exe) and about 600-700 MB of memory. More tabs, more memory...the sky's the limit, when it comes to Chrome.
By comparison, the very same tabs in IE7 would be about 200-250 MB.