The web interface used for Monit will automatically adjust column sizes based on the length of a monitor directive's name. This applies for the following sections (tested):
However, the section 'file' does not auto-size the column used to display the name of the monitor directive. This in turn wraps a monitor directive's name and turns it into a two-line entry. I'm assuming it should auto-size too, like the other sections, therefore reporting it as a (minor) bug.