My workflow is to open a browser window in the morning (restoring my previous tabs) then open additional tabs as needed. Over time, they build up to some steady state. If one doesn't get used, I eventually close it. I occasionally save the remainders to my bookmarks and might start reasonably fresh after that.

I don't read each of them multiple times every day.

Sometimes special occasions demand more - e.g. I have 5 WeatherUnderground tabs open at the moment: 1) Local weather; 2) Local Radar; 3) Regional Radar; 4) Hurricane Sandy; 5) Jeff Masters's WunderBlog on Sandy.

If one has enough RAM, one might as well use it all. :-)

Cheers,
Scott.