How to place a chart across multiple columns of a table in Report Builder/SSRS

Question

I'm trying to place a chart across multiple columns of a table in Report Builder (because I'm trying to emulate a colleague's chart. I tried creating a rectangle, but I cannot get the rectangle to span more than one column. Thanks!

Here's what I'm trying to achieve:

Here's what I have now:

Answer 1

The answer is just to merge the cells in the top row.

The reason why I don't want to have one column is that I need the interior table width to be smaller than the chart width.