Another issue the author didn't mention, but I sometimes encounter, is that when you copy richly-formatted tables to paste in Excel or some other software, it often includes unwanted HTML tags. I usually have to use regex or at least a search and replace to make the table sortable and filterable.
I imagine this could similarly be an issue with screen readers, but haven't tested it.
thats why all data should just be presented in an excel pivot table from the start