ANSWER: Dear Nancy,
thank you for your question.
The easiest approach I can suggest you, to be sure that your Excel file
will remain the same after having imported it into a PowerPoint slide is
to:
- Select the whole Excel file
- Click on Copy, from the Edit Menu, while you are still in Excel
- Go to the PowerPoint slide
- Click on the Edit menu
- Select "Paste Special"

- Choose Picture (Enhanced Metafile) and click ok

This way you should have your Excel file correctly inserted into a slide
with no data missing.
Please let me know if this does help you.
All my best,
Chiara Monetti