The following information is derived from the plugin description.

Make documents containing multiple columns comparable.

The comparison by default checks the documents line by line. In case of multiple columns in the document the line detection does not work properly. This will ususaly lead to large number of differences. This filter, when enabled, mitigates the effect by checking for a column structure layout and thus comparing the content of each column instead of line by line.

Please note: the filter is not suitable for table layouts.