Why is my table background image not showing in wordpress?

What does Firebug or Chrome Developer Tools report on the rendered background image URL? Does it return a 404?

Try changing this:

style="background-image:url(/wp-content/plugins/xxxxxxwidget/image2.png)

to this:

style="background-image:url(<?php echo wp_plugins_dir(); ?>/xxxxxxwidget/image2.png)