Killink CSV provides the following ways to resize column widths:

Manual Resize

When you move the mouse cursor over the column separator line the cursor will change to the resize column cursor as seen in the picture below.  Move the mouse cursor over the column separator line, and click and hold the mouse button while moving the mouse to the left or right.  Move the mouse to the left to make the column width smaller, or move to the right to make the column width larger.

Note: You an hide the column by moving the mouse to the left until the column is no longer visible or by press Ctrl+H.

Best Fit

Double click the column separator line to change the column width to fit the contents.

Auto-size to Best Fit

Mark the program option "auto-size columns to best fit" to have the each column's width resized to fix the contents when the file is open.  This option is available in the General Options section found by pressing the F8 key or selecting Tools > Options from the menu. (Note: This option is not available when the "remember column widths" option is marked.)

Remember Column Widths

Mark the program option "remember column widths" to use the same column width settings each time Killink CSV is launched.  This option is available in the General Options section found by pressing the F8 key or selecting Tools > Options from the menu. (Note: This option is not available when the "auto-size columns to best fit" option is marked.)