On Friday,  5 Jan 2018 at 09:28, Uwe Brauer wrote:

[...]

> The last row behaves strangely the cell in the second column is *not*
> empty but the cell in the third one is, nevertheless the cell in the
> last column contains the string nan, which I don't understand.

But the second column is *not* empty; maybe you meant 3rd column?

-- 
Eric S Fraga via Emacs 27.0.50, Org release_9.1.6