Alan Stone wrote:
>> the best you can do is to either make the fontsize smaller
>
> It would decrease the menu readability too much.
>
>> the area wider (less linebreaks)
>
> It would decrease the text area width too much.
>
>> or see of \startsimplecolumns ... \stopsimplecolumns
>
> Although I don't see how adding columns would provide
> a solution - the chapter/section titles are in french, i.e.
> usually longer than for ex. in english ( they could be
> shortened and then most would become meaningless)

in that case don't menu's just use local tocs in the text area and use
the menu to refer to them