To split an area of a page into multiple columns, use the Columns tab in the option window, as shown in figure 1.
The options on the left split the area into multiple columns of equal width. The options on the right split the area into two columns of unequal width.
You can split columns repeatedly to achieve complex combinations of widths. For example, you can split an area into a 1:3 ratio and then split the right column in a 2:1 ratio, which will produce a 1:2:1 ratio.
After adding in a column split, you will see the option bar for the option itself and an additional option bar for each column, as shown in figure 2.
The add button on the top option bar will add options above the column split. The delete button on the top option bar will delete the column split and any options added into it. The narrower option bars can be used to add options into the columns, as shown in figure 3.