Hi Pragati,
Thank you for the response but I think there has been a misunderstanding. When I said hyperlink I meant setting the .Hyperlink property on each cell. I have updated the example code you have provided to allow for more accurate timing and to better illustrate the issue. Please run the attached solution and do the following:
Change the number box to 50000
Leave the links box unchecked and hit the button
It should take a couple of seconds to produce the file. (for me it is about 1,500-1,800ms)
Now check the links box and hit the start button again
It should take significantly longer and drive one of your CPU cores at 100% while it is working (for me it is about 40,000ms)
Hopefully this better illustrates the issue. If you take some time to change the number of rows and experiment you can see that the time taken to create the sheet scales roughly linearly with the number of rows, however the time when adding hyperlinks to the cells is not linear but something far worse.