In normal HTML for browsers, making elements overlap is easy.
But in the dark world of HTML email, where the motto is \"code like it\'s 1996\" because Outlook uses
A little late to the conversation, but this similar answer is the technique you are looking for.
Your example is a lot more complex however as you are spanning over both rows and columns. I'm up for the challenge:
Title Here
Image Here
Column
...
...
...
Heading 1
Content
...
...
...
This is as close as you'll get. You can't make non-rectangles, so the top Header in the body has to be in it's own cell.