Are you wanting to display it on the page as you would see it in Excel? Or simply link to it?
Your post seems to imply the former. If so, does it simply need to display or does it need to be interactive as Excel offers? If it simply needs to display you would make a screen capture of it and display the image.
I can't have an image because the text needs to be searchable. I figured it out, although it was a long way around, I saved the excel spreadsheet as an html page and then inported the html page into my project, then opened the page via my project manager/ html files, then copied the table I needed into the topic page where I wanted it, phew! Seems odd that robohelp does not have a simple insert function that accepts xls file, but whatever.