Load the page then fetch data using JavaScrip via an Ajax call. Ajax is very easy to implement using jQuery.
Example: Untested!! But its something like this..
<head>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js" ></script>
<script>
// Run on page load
$(function() {
$.ajax({
url: "getMyData.html",
type: "GET"
}).success(function(data) {
// My data is in "data", if it is html then
$("#myDiv").html(data);
});
});
</script>
</head>
<body>
<h1>Hello</h1>
<div id="myDiv"></div>
</body>