Thanks Rahul. Watched many videos to understand ABAP, finally found the best channel to learn ABAP. Thankyou so much!!!! Waiting for HANA playlist :) .
Please refer the videos of CALL SCREEN and LEAVE to SCREEN in Module pool playlist. Same concept is applicable to CALL TRANSACTION and LEAVE TO TRANSACTION. Video no - 56 to 58. ru-vid.com/group/PLM3lhmHjSeITYl3Jz1dx1l0faMUsik8lV&si=RToOOcjPGaU_XtDJ
I tried ME21N, there we have a option to add one tab Customer Data, if SAP has provided multiple subscreens, then yes we can go for multiple custom tabs.