@nikhilpowar97 If you right click in the Task Activity window, you can export as xml, csv, txt or html. Once you open the format you've selected, you can print to pdf (depending on your computer settings) but I don't know of a way to automatically get the listing as a pdf.
You can also export a certain date range of tasks on the System tab then Load/Extract (not the one under the Application tab). Click the export tab, then select Task Activity on the file type drop down and set your date range then extract. Still doesn't pop as a pdf, but offers a little more flexibility on dates to include.