Evening Out Tables - Table On The Right Is Not Even With The Table On The Left

As you can see, the table on the right is not even with the table on the left. This code has worked in the past,

<script type="text/javascript">
window.onload = function () {
var divArray = document.getElementById('tablecontent').offsetHeight;
var subtraction = divArray - 442;
var tablesidebar = document.getElementById('tablesideba');
tablesidebar.style.paddingBottom = subtraction + 'px';
};
</script>

But that only works for a static page. The problem is now, both tables, the one on the left, and the one on the right, are dynamic. Either could have different heights depending on what page you are visiting. Different pages also have more than one table, and the only way I could see this working is with a million if statements or each page, defining each table being used. Is there anyway to get these two tables evened out, no matter the content using JavaScript?