@Kirkburn wrote on the discussion thread:
This is not currently allowed, sorry - but it is a concern we recognise.
However, I should mention that we discourage using wide tables. As mentioned elsewhere, a very large proportion of visitors are on mobile devices these days, and wide tables will invariably have issues displaying on them. It's a good idea to see if tables can be redesigned to fit smaller widths, perhaps by using two rows of data for each item (potentially halving the number of columns).
this page's right sidebar has been moved to the bottom, like how the responsive layout automatically moves it to the bottom on smaller screens.