What would cause a single webpage to load slowly? I have javascript within the <head> element. The html consists of 2 <div> elements and within these <div> elements are a bunch of <table> elements and that's it.

The functionality of this site is such that each <table> element contains data that during the "onload" event, these <table> elements are hidden. Each <table> elements is controlled by an HTML menu (the menu itself is an html table). When a menu item is clicked, it will either display or hide the <table> element depending on whether it is already displayed or hidden.