Is it possible to get JSP response by using Ajax?
Yes, the response of the AJAX call will be the content of the DIV that you want to update. In your case, when you click contractor # 3 for example, the table will be updated. So your AJAX call will hit a servlet which will forward to a JSP. JSP will return the table content.
<div id="orders">
JSP return content here.... orders table thing for the chosen contractor.
</div>
JSP will have content like.
<table>
<tr><td>${"param1"}</td><td>${"param2"}</td></tr>
</table>
Do not use XMLHttpRequest directly. If you are allowed to do so, use jQuery. Disclaimer: I have not tried this. Please check exact syntax etc. I am trying to help you get started.