def _is_tabular(structure):
    """ Determines if a PDS4 structure can be shown as a table.

    Tabular structures are either:
        (1) Tables, or
        (2) Arrays

    Parameters
    ----------
    structure : Structure
        PDS4 structure to check.

    Returns
    -------
    bool
        True if *structure* can be displayed as a table, False otherwise.
    """
    return structure.is_table() or structure.is_array()
