I have just released an extension called
TableSpans.HtmlAgilityPack for HtmlAgilityPack to handle collapsing rowspan and colspan into unique cells to aid in parsing tables.
If you try to parse a table that makes use of colspans or rowspans, you'll find the results of the parsing fail completely. This package rebuilds the individual cells duplicating the results across the missing cells.
See the example image below:
Example table found here: https://stackoverflow.com/questions/16693349/complicated-table-using-rowspan-and-colspan