If I see a typo, then I usually figure that the ethnic restaurant is more authentic!

I'm not so sure when it's not an ethnic restaurant though. I have a specific situation in mind here: I started helping my (Japanese) mom with her business after I moved here, and she has a restaurant that offers a "Tuna Delax Salad". Typos really bother me, but I feel bad correcting my mom's English - especially as she'd have to reprint all the menus. Plus I feel like (hope?) that my mom kind of gets a pass since she's not a native English speaker. But I'm not 100% sure...

Do typos and grammatical mistakes in menus add charm to ethnic restaurants? What about other types of restaurants?