UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36

Steps to reproduce the problem:
1. Open attached test.html file in Chrome
2.  Highlight "example1@example.com", copy it, then paste it into the textarea below.
3. Double click "example1" to highlight it, then hold Shift and click just after .com to highlight all of "example1@example.com", copy it, then paste it into the textarea below.
4.  Highlight "example2@example.com", copy it, then paste it into the textarea below.
5. Double click "example2" to highlight it, then hold Shift and click just after .com to highlight all of "example2@example.com", copy it, then paste it into the textarea below.

What is the expected behavior?
2.  "example1@example.com" is pasted
3.  "example1@example.com" is pasted (without a tab after it)
4.  "example2@example.com" is pasted
5.  "example2@example.com" is pasted (without a newline after it)

What went wrong?
See attached video.
For step #3, a tab is added at the end.
For step #5, a newline is added at the end.

Did this work before? N/A 

Chrome version: 69.0.3497.100  Channel: stable
OS Version: OS X 10.13.6
Flash Version: 

I'm pretty sure this is because you want to copy the table as a TSV.  I don't think you want to break that, but if a single cell is copied, I don't think it should have a tab or newline appended.
Also, testing on Firefox 62, it behaves as I'd expect.  On Safari 12, it behaves like Chrome.
 

Deleted: test.html 345 bytes

test.html 345 bytes View Download

Deleted: copyPaste.mov 474 KB

	copyPaste.mov 474 KB View Download