Today, Knovel is releasing an upgrade to the tables with new usability enhancements and interactive tools that you’ll want to see for yourself. Check out screenshots here. Note also at this webpage, they advertize lots of online demonstrations, called Quickstart Webinars. They are free.
Princeton University’s link to the Knovel database:
Knovel Engineering and Scientific Online References
Collection of the latest leading technical and engineering reference books.