But maybe if you were the only German in the office you might be offended by the implication?

What if they do actually see you as a Nazi though? Because I would wager that whoever wrote that message was expecting that the message would be read by a Zionist.

Don't get me wrong, I get what you're saying about not taking a sentiment personally if you know that you're not the intended audience. For example, I have many trans friends, who sometimes make jokes where cis people are part of the punchline. Although I'm cis, I don't take it personally because I know that being witness to the joke at all means that I am not the kind of person who is being joked about — indeed, it makes me feel privileged to be trusted enough to be within the "safe" bubble for my trans friends.

However, in this case, if I think about how I would feel if I were an anti-zionist Jew who received this meal, I'd feel pretty shitty because it would remind me of how gross it feels that Israel equating Judaism and the Israeli state makes Jewish people everywhere less safe; a fucked up side effects of Israel's atrocities is that even loudly anti-zionist Jewish people are at risk of increased antisemitism (genuine antisemitism, not just attacking the state of Israel and/or Zionist stances). It would feel shitty because no matter how loudly you scream "they do not speak for us" (an act that will get you condemned as being anti-Semitic, even if you're Jewish), Israel is not facing the kind of opposition that's necessary.

Part of how we resist Israel is by not letting them define themselves as synonymous with Judaism. I respect the intention of the person who wrote the message on the meal, but I believe the act itself to be misguided due to ultimately reinforcing Israel's preferred world view. It's important to remember that genuine antisemitism (i.e. stuff aimed at Jewish people rather than at Israel) is useful to Israel, because it helps them to manufacture consent for the ongoing genocide, and generally fuels the Zionist project