Why is safari using 1.75gb of real memory?

I own a 13 Macbook Air with 4gigs of ram. After upgrading to Lion and spending some time browsing I noticed scrolling had become very slow and laggy. I opened activity monitor to see the memory use of my programs and found Safari Web Content using 1.75gb and Safari another 600mb. That only left me with 30MB of free memory.
I forced quit Safari Web Content and it restarted making very little use of memory. Scrolling became fast again and my free memory went to almost 2gb. Since then and as I continue to browse Safari Web Content uses again more and more memory obviously storing every web page to ram.
Is there a way to manage how much content I want it to store so that it does not use up all my free ram? At preferences my database storage is only at 5mb.
Thank you.

 

I see there's already a thread about this. Sorry for the double post.

http://forums.macrumors.com/showthread.php?t=1181523

 

I tried that now that you mentioned it but it did not alter the ram used by Safari. I'll read the other thread to see if they found a fix. Thanks.

 

I disabled adblock and my problem went away. Hopefully Apple will provide a a solution that lets us make use of our extensions.