Thanks for your query.
Aspose.Cells does support to read/manipulate HTML file or save it to MS Excel file formats (e.g XLS, XLSX , XLSM, XLSB, etc.) But, generally, we support MS Excel oriented HTML files. Common HTML files are not completely supported. For example, you open your HTML file into MS Excel manually and save to XLS/XLSX. The resultant file would be the output file. The same thing can be done via Aspose.Cells APIs.
If you find any issue where MS Excel does support certain things and Aspose.Cells does not do well, please share your HTML file, we will check it soon.