You can always find the answer you want to find by googling it.
Just saying.
Alternatively you can read his books and come to a more sensible view that isn't based on a few random quotes. When I read his description of his time in Tanzania, I could easily see it misinterpreted by someone with no sense of how big the cultural divide was, ie, someone who thinks that Tanzanians were culturally identical to Dahl, just not white (which they weren't and aren't). But if you insist on a quote, here's one from that chapter:
In those benighted days of Empire it was considered impertinent for a black man to understand English, let alone to speak it.
(Therefore, Dahl leaned Swahili, which puts him one up on most of us on this thread). Hardly pro-Empire.
As for the anti-Semitism, I'll believe that when the quotes are properly referenced. Even then, considering that he fought in the Eastern Med, flying a Hurricane in extremely hazardous circumstances and nearly died in the process, armchair accusations of anti-Semitism are a little lazy, to be honest.
Someone above referred to a story where an Indian is verbally abused by a British person. It's clear that the latter is being an arsehole, and the story certainly doesn't suggest that the Indian was being put in his place.
Accusing people like Dahl of racism casts the net so widely that it devalues the accusation of its seriousness. He wasn't racist and nor were his stories.