Joginder,
I have confirmed the issue, and put it at the top of the todo list. Right now we're at the end of v2 release (which has some other important new features), and for that release we won't have the time to look into this. Also, unfortunately, we did not have the time to include the index feature in it. But we will make a hotfix release shortly afterwards, which will contain the index feature that I promised you (it's in the works, just not complete yet), and hopefully we'll be able to speed up drawing of tables in your sample (the slowdown is related to drawing, not to document generation). Hopefully within a couple of weeks I'll be able to give you the hotfix.
Thanks.