These two phrases mean basically the same thing. Together they emphasize that God punished them immediately, even while they were eating the meat. AT: "While they were still eating the meat" (See: [[rc://en/ta/man/translate/figs-parallelism]])
This can be stated in active form. AT: "They named that place Kibroth Hattaavah" (See: [[rc://en/ta/man/translate/figs-activepassive]] and [[rc://en/ta/man/translate/translate-names]])