Hi
Recently I had to deal with tables with large cells. Googling around the best solution I found is https://github.com/kjambunathan/org-mode-ox-odt It even allows to export to latex, besides odt. Works like charm. Besides its amazing features I have to add that the author was extremely responsive and willing to enhance the features. I am deeply impressed and can only wholeheartedly recommend this package. Regards Uwe Brauer