I'm working on Solaris sunray or a fedora linux Laptop, so I'm using
OpenOffice on Solaris and LiberOffice on Fedora Linux.
If you want to insert multiline text in a cell in OpenOffice or LibreOffice Calc ( this is the Microsoft excel in the free world ), you have to position the cursor
into the Cell and not the input line just below the toolbar.
In the cell itself a manual line break can be inserted by pressing <strg>-<return> you get a linebreak of the text in the cell, which improves formating.