OS and versions : Ubuntu 18.04, LibreOffice 18.104.22.168*
Export/import a table between MySQL and LO Base functions well using Calc sheet as an intermediate table
(with import/export facility of phpMyAdmin on MySQL side, and copy-past from LO side)
Except for line-breaks in multi-line fields. So far, I did not find any way not to loose the line-breaks in the process.