Dividing Lines in Visual Mode
To divide a line, use the V (diVide) cut-and-paste function in column 3 or 4, then insert the special field separator ("~") at each division point in the line. The default field separator is tilde ("~" ), but you can override this with Set Vis Field. If no "~" is found in the line, a blank line is added after the line.
What about dividing all the lines in a range? Use VV to mark the start and the end of the line range, then place the field separators in the first line of the range. Every line of the range is divided at the specified field columns. If no "~" is found, a blank line is added after each line.
When marking several division points, insert them into the first line of the block from right to left. As you insert them, they shift the following text to the right one space each. Otherwise, if you insert them from left to right, it is difficult to select the proper division point for subsequent fields.