I was facing the same problem on Linux, what I did was to select all the content (ctrl-A) and then press ctrl+shift+L, It gives you a cursor on each line and then you can add similar content to each column.
Also you can perform other operations like cut, copy and paste column wise.
PS :- If you want to select a rectangular set of data from text, you can also press shift and hold Right Mouse button and then select data in a rectangular fashion. Then press CTRL+SHIFT+L to get the cursor on each line.