def METHOD_NAME(self, parent, block):
    """
    Ensure first two rows (column header and separator row) are valid table rows.
    Keep border check and separator row do avoid repeating the work.
    """
    is_table = False
    header = [row.strip() for row in block.split('\n')[0:2]]
    if len(header) == 2:
        self.border = header[0].startswith('|')
        row = self._split_row(header[0])
        is_table = len(row) > 1
        if is_table:
            row = self._split_row(header[1])
            is_table = len(row) > 1 and set(''.join(row)) <= set('|:- ')
            if is_table:
                self.separator = row
    return is_table