Adjusting the height and width of the table should automatically adjust the font size as well.
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>jQuery UI Resizable - Default functionality</title>
<link rel="stylesheet" href="//code.jquery.com/ui/1.11.4/themes
/smoothness/jquery-ui.css">
<script src="//code.jquery.com/jquery-1.10.2.js"></script>
<script src="//code.jquery.com/ui/1.11.4/jquery-ui.js"></script>
<link rel="stylesheet" href="/resources/demos/style.css">
<style>
#resizable {
width: 150px;
height: 150px;
padding: 0.5em;
}
#resizable h3 {
text-align: center;
margin: 0;
}
</style>
<script>
$(function() {
$("#resizable").resizable();
});
</script>
</head>
<body>
<div class="ui-widget-content">
<table id="resizable">
<tr>
<th>I want to resize this font-size, directly proportionally while resizing this table</th>
</tr>
</table>
</div>
</body>
</html>