you need to add reference the datatables js and css files, for example
<script src="https://code.jquery.com/jquery-1.11.1.min.js"></script>
// JQuery Reference, If you have added jQuery reference in your master page then ignore,
// else include this too with the below reference
<script src="https://cdn.datatables.net/1.10.4/js/jquery.dataTables.min.js"></script>
<link rel="stylesheet" href="https://cdn.datatables.net/1.10.4/css/jquery.dataTables.min.css">
refer below article:
jQuery Datatables For Beginners[
^]