I think what you are trying to do is actually display the textual contents of the Excel document onto your HTML page in a table data cell separated fashion. Is that correct?
It sounds like what you've done is setup an IFrame with the SRC attribute pointed to the location of the Excel document in an attempt to display it on the page. Which won't work, because when the IFrame loads it will load the file, which will then prompt the user to download it because of its file type. It won't simply be interpreted by the browser and displayed.
If what I'm saying is accurate, what you'll want to do is use ASP to read the contents of the excel file and then spit out the contents onto your page in whichever fashion you like.
Let us know if this is correct, because we can assist you with that.
Sincerely,
Mark