Thanks to "Chris C" clarifying how to re-style the WebResource so that it takes up only the amount of space that you want it to take up instead of what MSCRM does by default.
I've taken the liberty of reproducing his comment below in case the blog post eventually goes "poof".
Hmm, looks like the HTML messed up in my last post! I'll remove any formatting which is going to mess it up this time :)
The reason you need to specify 2 rows is that the CSS isn't removing all the margins around the text and as such it's taking up more space than it appears.
I can successfully use 1 row with the following CSS changes:
body style="border: 0px 0px 0px 0px;
margin:0px 0px 0px 0px;
padding: 0px 0px 0px 0px;
font-family: Segoe UI, Tahoma, Arial;
font-size: 11px;
font-weight: bold;
background-color: #f6f8fa;"
Hope that helps!