To insert and embed an Excel spreadsheet into OneNote, follow these steps:

1. Open the spreadsheet you wish to embed and select the area you want to display.
2. Open OneNote and navigate to the page you would like to insert the spreadsheet into.
3. In the ribbon at the top of your window, select ‘Insert’ and click the ‘Spreadsheet’ icon.
4. Highlight the area you have selected from the spreadsheet to copy its contents.
5. Right-click the highlighted area and select ‘copy’ from the pop-up menu.
6. Go to the OneNote page where you would like the spreadsheet to appear, and right-click to paste it.
7. Choose between inserting the entire spreadsheet or just a link to the original file.