I have heard two stories told to explain this. One is, it used to be that acting and movie-making was considered a "low" thing to do, so a marginalized but white-looking minority got pushed in to doing it. Hollywood was low-status so long ago that there's no way the ethnic bias could still be around so I don't believe that theory.

The other one is that Jews have a high IQ average, so you find them in important positions more than you would otherwise. I used to think that was a fringe internet blog theory, but apparently the mainstream pop psychologist Jordan Peterson professes it: https://www.jordanbpeterson.com/psychology/on-the-so-called-...

Jewish people get more Nobel prizes, have higher SAT scores, and are overrepresented in so many things that the average IQ theory seems like the most reasonable explanation. This comes with the mandatory disclaimer that the variations between individual people are much larger than the differences between ethnic averages: making it useful for sociology on a mass scale but useless for understanding any individual person.