I was using ODATA in single tenant, it worked fine.
But when I want to use it in excel, I think this is not possible since excel does not know the "tenant".
I see a workaround : create a webservice independant for each service, exposing ODATA on different port.
Do you know a better solution ?
Afterwards , i'll to look into : #815@7b73e6f2-1140-4638-984c-1d3d497d71cb because we'll need to secure ODATA in excel.
thanks for your help :)