Hi Rob,
You can use an iframe to do this. In a nutshell:
1. Share the spreascheet online: https://support.office.com/en-us/article/share-it-embed-an-excel-workbook-on-your-web-page-or-blog-from-onedrive-804e1845-5662-487e-9b38-f96307144081
2. Add a topic section to your frontpage: https://docs.moodle.org/36/en/Front_page_FAQ#How_can_I_add_text_and_a_picture_to_the_centre_column.3F
3. Add the iframe to this topic section: https://docs.moodle.org/36/en/Iframe
Cheers,
Johan