Try the following:
(1) Upload the Excel file to the document library
(2) Open the Excel file in the browser
(3) Click on Share in Excel Online and click on Embed
(4) On the Embed window select what you want to embed and grab the iFrame code
(5) Go to your SPO modern page and insert in the canvas a Embed WebPart
(6) In the Embed WebPart configuration panel just paste the iFrame code and you are done!