Even when "Select next row" does the job, we still need to make a distinction between "selected text" and "selected rows" eventually, so I do think that adding some logic to text selection would be helpful to just press "shift" + up/down arrow and press CTRL + J, Studio being able to recognize seg. # information and perform "Merge" operation.

But thanks again, Jerzy. I was struggling with massive "merge" operations needed today and this really saved a lot of time. :) 

*realize (autocorrect...)

YOU ARE COMPLETELY RIGHT! I didn't realice "Select next row" performed like that, being completely honest. You just made my day

BTW, the shortcut for selecting segments you need to perform merging is "Select next row". So just check which shortcut is assigned there and use it.

Well, but this is already there... You can change the shortcut for merging segments to whatever you want. And it is already possible to select segments in target with a keyboard shortcut (NOT the same as in Word) and merge the segments, even over the paragraph marks. So why change anything?