Improve speed of object-to-html transform in javascript?
If this is on an intranet, with similar machines running this JS, then 2 seconds is fairly ok for 4,200 records...but if its on the internet, you might want to think about doing this server side and just ajax'ing the server generated table code via js...someone running this on an iPad would probably take considerably longer to generate 4,200 records vs someone running an overclocked i7 machine for instance. Just food for thought. 

As for actual improvements to the code, I don't really see any glaring items...although someone else might want to pipe in. Seems someone already piped in :)