Laying Out List Pages 
The layout of a list page determines how clearly structured, and therefore easy to read, a list is. It is not the amount of information gathered on one page that is important, but the way the information is presented. The human eye can cope much better with small blocks of data. And it is equally important that columns or lines containing a new block of information are separated visually from the preceding blocks. When laying out a list page, you should use several blanks or vertical lines to separate individual columns. Before outputting lines that contain a new item of information, draw a blank or underscore line.
The following topics explain the possibilities ABAP offers for laying out list pages.