What is .XLSMHTML file?
Archived MIME HTML spreadsheet file saved by earlier versions of the Microsoft Excel spreadsheet application; contains HTML code that represents the spreadsheet in a format similar to the original .XLS file; used for viewing published spreadsheets in a Web browser.
XLSMHTML files are no longer supported by Microsoft Excel. If you would like to publish the HTML version of a spreadsheet, you should use the .MHTML or .MHT extensions supported in Excel 2010.
Recommended Software Programs to open .XLSMHTML file