I have a code snippet that looks like something below. The full code can be seen here: http://codepen.io/anon/pen/VYbxbQ
<table style="display: inline-table; width: 1220px;">
<div style="height: 440px; width: 280px; background: #000;"></div>
You are mixing colspan/rowspans with defined widths and heights, which would make this layout very difficult to predict, as you are experiencing right now.
If you are doing this for layout purposes, I'd recommend against using tables. Check out this Stack Overflow question for more info.
Try using a grid layout. There are ton available, like Bootstrap and Foundation.