assume there is a paper written by Foo and Bar.
When there is a citation, I want to show sometimes(!) only the first author (Foo) and the rest of the time all authors (foo/Bar). The reason is that I have table and the first column is for the paper citations. However, the column has fixed width, therefore sometimes i get an ugly result if there are more than two authors, see:

I am using scrbook.
natbib,biblatex, ...)? A MWE would be very helpful indeed. Apart from that, it is really not a good idea to use one citation and at times another - it will confuse the reader. – moewe Sep 28 '13 at 13:13\nocite{<key>}so it is included in the bibliography. You would lose the hyperlink, but that is surely better than what you have right now (judging by the image in the question).... – jon Oct 10 '13 at 00:50