In current groff (1.23.0), table is rendered thus


                +---------------+---------+--------+----------+--------------+
                |   Typeface    |  Roman  |  Bold  |  Italic  |  Bold-Italic |
                +---------------+---------+--------+----------+--------------+
                | Dutch         |  TR     |  TB    |  TI      |  TBI         |
                +---------------+---------+--------+----------+--------------+
                | Swiss         |  HR     |  HB    |  HI      |  HBI         |
                +---------------+---------+--------+----------+--------------+
                | Swiss Narrow  |  HNR    |  HNB   |  HNI     |  HNBI        |
                +---------------+---------+--------+----------+--------------+
                | Courier       |  CR     |  CB    |  CI      |              |
                +---------------+---------+--------+----------+--------------+
                | Elite         |  ER     |  EB    |  EI      |              |
                +---------------+---------+--------+----------+--------------+
 
  There is thus no need to format all columns in the header line as
"centered" (C).

  That will also eliminate the creation of a trailing space in the last header
column.

  Adding a '\&' as a data in the last (empty) column in the last two lines
will also eliminate unnecessary trailing space
(which is removed each time this man page is rendered,
instead of never creating it;
not reported by the upstream version).