The prohabtion to talk during kriar hatorah is dated back to the gemorah as
The Gemara records a prohibition to talk during krias haTorah ,1 and the Zohar explains that one should envision that he is standing at Har Sinai and receiving the Torah (and due to the great seriousness of the time one definitely shouldn’t Talk then).2
It is interesting to note that he Alter Rebbe adds that for this reason some Jews were particular to shake during kriah as the Jews did at Matan Torah.3
Can I learn torah during krias hatorah?
Learning during laining is likewise prohibited being that one is to focus on listning to the actual torah portion which is being read at the time. However, poskim write that is a urgent question comes up one may nevertheless answer an urgent shaila,4 so to one can stop someone from transgressing (la’afrushi mei’issura). Yet, in any case if it is possible one should stop him by motion without speaking.5
However, One who already heard kriah already may learn quietly during laining if without him there is a minyan listening and additionally he turns away or distances himself before kriah begins to demonstrate that he isn’t part of the minyan (and therefore he is not disgracing the kriah as it is evident that he isn’t part of the minyan).6
In between aliyos
Regarding the breaks between aliyos (bein gavra lgavra), rishonim are divided if one can talk then :7 Some say that the prohibition only pertains to the time of laining, while others argue that the prohibition was instituted for the entire duration of kriah, lest one come to continue his conversation during the laining.8
How about learning in between the aliyos?
Learning between aliyos is subject to a further question. Some say that according to those who prohibit talking, learning is likewise prohibited,9 while others hold that learning on one’s own does not pose a problem.10
In practice Contemporary poskim write that today when the aliyos are spaced with long mi-shebeirachs one may rely on the lenient opinions to learn Torah during that time, but not to converse with others.11 (poskim permit saying something quick and important). 12
Another important point Acharonim note that listening to the mi-shebeirach and answering amen helps the bracha materialize and it is therefore appropriate to listen and especially answer the mi-shebeirach.13
How about wishing mazal tov in between aliyos?
contemporary poskim write that one may wish mazal tov since the reason for the prohibition to talk between aliyos is so that one won’t continue talking during the aliya, and with a short mazal tov we aren’t concerned.14 Some poskim add that wishing mazal tov is sort of a mitzvah (or at least kavod habriyos), which is also allowed in this circumstance.15 therefore, in practice one can wish Mazal tov .
