Each column has a fixed width of 200px with a 20px margin.
The top-left box and the columns have variable height.
Like this

Tor Valamo kindly provided an answer to a similar question (that being elastic, this is fixed), but I cant centre the layout, as it uses position: absolute.
How can I do it? I know that using a table with colspan and rowspan the answer to this problem is trivial, but I would like to avoid table-based layout like the plague!
Not sure I understand exactly what you’re asking, but something like this…?