Thanks for providing us template files.
I have evaluated your issue/case a bit using your template files. It looks like your template HTML file is a common file and not Excel oriented (For your information, Aspose.Cells supports to convert/process Excel oriented HTML file to other file formats properly). Anyways, I have tested your case a bit using the following sample code with your template HTML file. I observed that not each content of HTML file is rendered (apart from Aspose.Cells does not support CSS, MS Excel also prints error when opening the HTML file into it) to SpreadsheetML (.xml) file. I can see it is not converting “Applies To:” contents at different places in the output file:
HTMLLoadOptions opts = new HTMLLoadOptions(LoadFormat.HTML);
Workbook workbook = new Workbook(“f:\files\4617 AU16.htm”, opts);
I have logged a ticket with an id “CELLSJAVA-41763” for your issue. We will check if we could support such a file and convert the missing contents in the output XML file.
Once we have any update on it, we will let you know here.