When opening the widget, the default column widths might be too narrow to display all of their content. You can manually resize a single column by dragging a column separater bar, as shown.
You can also change the width of all columns in the widget so that each column is wide enough to show its full value. To resize all column widths to fit the data:
Right-click on any column heading to display the column heading context menu.
Select Fit all columns to content.
All of the column widths in the widget change to fit the widest value in their respective columns. Some of the right-most columns might no longer be visible, but you an resize the widget manually, as desired.
You can choose which columns you want to display from the widget's Settings, or you can use the context menu from the column headings. You can also set the text alignment for each column.
To configure the columns you want to show: