How did this device worked?
 

Well, in the 1937 and 1938 telephone directory for Bucharest they mention an device called telematon: http://lcweb2.loc.gov/cgi-bin/displa...splayProfile=0
In Romanian it's saying something like: TELEMATON: Allows automatic calling of numebers dialled often, without hand dialing them, like usually. Saves time, avoids efforts. Recomended for persons that are having calls with the same number often.
Romanian expressions can be very tricky. "Cari" is an archaism for "care" ("which"). Not to be confused with "carii" - singular "carie" (dental cavities or that small insects that are diging thin tunels into the wood in order to eat it - carii de lemn).

So how did it worked? Never seen one for real. Durring communism they where not shown any more on telephone directories (they might have been in use, but not presented).
Since the Romanian telephone and telegraph company (telex wasn't used back then) was U.S.A. owned it might resembled with something American.
Here are some other ideas: https://www.wasser.de/telefon-alt/fo...00000000003531

Hard to tell, but if I had to guess from the description alone, I would say it was the mechanical or electromechanical equivalent to a 'modern' speed dialer. You know, one of those old fashioned boxes you plugged into the phone line next to the phone, with lots of buttons having programmable phone numbers stored on each one, for speed dial.

During communism, it was probably considered a bourgeois capitalist extravagance.

It would be neat to see one of those things, it's probably very mechanically complex. It would probably have to be like multiple programmable rotary dials in one device, with the ability to pause between each number dialed. Probably looks like a mechanical adding machine inside.

We had one at the shop. It ran on a roll of plastic like a player piano.
You colored in boxes with a pencil to program it. Must have read
it with light. It was from Radio Shack back about 1972.
Very limited, slow & noisy.

73 Zeno:smoke:
LFOD !

So it had a punch tape and reader, like an teleprinter?