I brought this up with Stephen Smith at least 10-12 years ago when he came to Australia and he looked surprised and said "that's silly, that should definitely be an import\export field, I'll look at that when I get back", guessing he lost his notes but it's never happened and it is SOOOOOO frustrating.
Yes you can dump and load the data and copy that file in but that's a ridiculous workaround when it's a simple table that should easily be a file export\import.
Every time there's an upgrade I hope this easy fix has been added but no....
Totally agree with you.

It sure is 'silly' and voting on it on the Ideas forum is like sending something into a black hole.  Maybe, just maybe someone from Sage is listening here ;-)