Ammar, With Firebug I had a look at the network traffic when I click a data point to edit it: I was surprised to see none.
IMO this is not good: it means that all the columns for all rows are in memory, making the browser able to handle far less rows.
Is there a reason why you are reading the complete rows to generate the plot? I expected that you would just read the necessary columns, then use AJAX to read a complete row when the user wants to edit it.