Hello,
Thank you for posting here in Microsoft Community.
As per checking on the screenshot you have provided, you are most likely replying to a plain text email which does not support bold or italic text, colored fonts, or other text formatting and photos. This is why you are getting this prompt, what I suggest is you can switch the formatting to HTML. The default text formatting may depend on what email you are replying, in case it's not default as HTML you can always feel free to change it.
Here's how:
- In the reply box that is currently open, click on Format Text if you happen to not see it, you may need click the Pop Out first.
- From there change the Format to HTML. Then try pasting the table again.
I hope this helps!
Best regards,
Arquel C.
Microsoft Moderator