colspan is really only intended for
th element inside a table header
As you can see from : http://codepen.io/Paulie-D/pen/IvFHe if you apply it to a
tr it does span 2 columns but it adds another column which you don’t want.
I don’t know how the information is being generated by to get the effect you are after you may have to use multiple tables, but, as I said, I’m no expert.
If you apply to the
th you get this.