This is very interesting. Here's a bit of background history.

One of the first antisemitic laws passed by the Nazi government was the Gesetz zur Wiederherstellung des Berufsbeamtentums (Law for the Restoration of the Professional Civil Service) of April 1933 which allowed for the firing or early pensioning off of all "non-Aryan" state employees. This included all kinds of Jewish artists employed by state orchestras, theatres, etc, as well as writers.

As a reaction to these massive layoffs, a Kulturbund deutscher Juden (Cultural Association of German Jews) was established in many cities to provide employment to Jewish artists by staging performances, shows, lectures and concerts, as well as publishing literature. These associations were private initiatives but they were tolerated by the state and eventually they were forcibly incorporated into one Reichsverband der jüdischen Kulturbünde in Deutschland (National Federation of Jewish Cultural Associations in Germany). All Jewish artists were required to be a member of the Reichsverband if they wanted to perform or publish. And everybody who wanted to attend a performance had to apply for membership as well. That is what these cards are about.

By September 1941 all Kulturbünde were abolished as the Nazis began deporting German Jews to the East.

Source: Kulka, Otto Dov. Deutsches Judentum unter dem Nationalsozialismus. Vol. 1. Mohr Siebeck, 1999.