That helped. It is the "table import" problem.
Looking at your screenshot of the data in TextEdit, each line begins with a leading tab character. When I create the exact same thing as what you did, it pastes into Numbers incorrectly exactly like you are seeing. You will also see an oval "box" pop up near the upper right of the window that says "Table data was imported". That's the signal it is going to get screwed up, that it is doing something other than a simple paste.
If you remove the tab characters from the beginning of each line in TextEdit, the data will paste into Numbers correctly. I have no solution for you if you want to import the entire table of data from your last screenshot. It will become "table data" and will go through that same "import" process and get messed up.
This has been an ongoing problem ever since Apple made this "feature" a long while back. The app is trying to be too smart and is instead being really stupid with no way for the user to correct its mistakes. I hope Apple fixes it. I do not recall what, if any, solutions or workarounds have been created here in this forum. Maybe someone else has a workaround for the general case of importing or pasting in tabular data.