When I saw the characters 吃吧 at first, I thought that maybe he was telling you to eat
Although I used to always include 儿话音 when I type/write, a friend in Beijing told me that people usually say it but don't type it (I evidently type Chinese more often than I write it!). I suspect this might be true a lot of the time (even though I have seen it written sometimes).
上班儿 vs 上班; 事儿 vs 事
We'll see the native speakers say!
PS. Just to confirm (since this is a bit of a confusing point which I myself didn't understand for years): are you talking about the Beijing pronunciation of "chi" which has an "r" sound and sounds like "
chirp"? In that case, it is not 儿话音 even though it sounds like it--it is simply a Northern pronunciation of the syllable "chi" (which contains an "r" sound and would not be written "chir", as confusing/counterintuitive as that is). The syllable "chir" in pinyin, however (which is 儿话音), sounds like the English word "char" (in a rhotic accent) and can indeed be written as a separate character for emphasis。
EDIT: Oh sorry, avagacchami, I think I misunderstood your original post. I thought you were talking about the dumpling seller's name but you're talking about what he was 'calling out'/saying to you, right? In that case, I can tell you the answer, since I asked the exact same question about a zhi/shi/chi syllable once: the answer is no (for the reason mentioned in the PS above). [Chinese speakers: Do correct me if I am wrong, however!]
PPS: Ah, I must be a bit slow tonight.. "Chirba Chirba" is the name of the dumpling truck, right?