Remember that a tab-delimited TXT file is NOT a spreadsheet! You lose Excel formatting when saving as a TXT file.
If you want line breaks (and other formatting) in your product description text, then you must use HTML tags...
Will render as:
Our biscuits are the <b>finest</b> in the world.<br /><br />We make them using the finest ingredients.<br /><br />Here, we feature the chocolate creams and they come in the following sizes:<ul><li>Small</li><li>medium</li><li>large</li></ul>
Our biscuits are the finest in the world.
We make them using the finest ingredients.
Here, we feature the chocolate creams and they come in the following sizes: