Hi Dhanapal,
It looks like you misunderstood the question. The question is "why you actually need to perform scrolling actions manually?". When you need to click a specific object, TestComplete usually scrolls the object to view automatically. If you need to make a specific object visible (for example, to take a screenshot), you can use the scrollIntoView method which is much more reliable than scrolling via coordinates (considering the fact the coordinates may change in your case). If you need to verify a control's contents, you do not need any scrolling at all - TestComplete will be able to obtain the needed object's properties regardless of its position on the screen. So, you do not actually need to use coordinate-based scrolling unless your testing task is very specific.
BTW, if you need to verify contents of a web table, you can use the HTML Table checkpoint, which can be downloaded from the following page:
New TestComplete HTML Table Checkpoint – Simplify Creation of Tests for Web Applications