lightest browser for win xp

Hi, at work for our data research, we have to log into an online account with a browser (currently we use IE 7.0) and once logged in, we have access to the  message board. For our research, every single post has to be manually scanned by one of us. Sometimes theres 10- 20  new postings, so in that case it is easy for us to scan over them; I just hold the CTRL button and click each link. Then each page I click loads in a new tab. Once we finish scanninfg over each page, we close the tab and proceed to the next one.

But sometimes theres 40 or 50 new postings in a day. Sometimes on the weekends, there are up to 100 new postings, sometimes even more. What I try to do is click 4-5 links then pause untill the pages catch up and finish downloading all the content. Once the pages have fully loaded (the little spinny icon near refresh button stops spinning) I click 4-5 more....so usually I click 4-5 links, pause for 5-6 seconds, click 4-5 more links, ect.

However my problem is after 12 or more tabs load, the IE browser goes REAL slow, and I do controll alt and delete, and it shows a memory leak (300,000 k of memory being used)

As far as my system goes, its a decent laptop, a hp pavilion DV9000 searies.

Does anyone reccommend an easier way to view these posts? When I am limited to loading 10-12 pages only, I often forget and sometimes scan a page that I had already scanned over. If I load all the links first though, I cant make that mistake since after I scan over the post that tab gets closed.