Instead of using an external stylesheet, try embedding your styles between the style tags
External:
<head>
<title>Title<title>
<link rel="stylesheet" type="text/css" href="styles.css" />
</head>
Embedded:
<head>
<title>Title<title>
<style>
table.top_table {
background-image: url(images/top.jpeg);
}
table.side_table {
background-image: url(images/side.jpeg);
}
table.main_table {
background-image: url(images/main.jpeg);
}
</style>
</head>
This way if it works, you know that it has something to do with linking to the external stylesheet.
Else, you might need to double check your paths for the image url.
You might need to use the short version of the image extension. Instead of .jpeg use .jpg