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 "chir
p"? 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?