I am using linebreak for the concatenated field to break the line in to next line. I am getting unneccesary extra lines when I use border-bottom with line break.
how do I avoid unneccesary lines?

DEFINE FILE CAR
CR/A1 = HEXBYT(13, 'A1');
LF/A1 = HEXBYT(10, 'A1');
CRLF/A2 = CR || LF;
COUNTRYNAMECAR/A100= COUNTRY || CRLF || CAR || MODEL;
END
TABLE FILE CAR
PRINT COUNTRYNAMECAR
CAR
WHERE RECORDLIMIT EQ '10'
ON TABLE SET STYLE *
TYPE=REPORT, LINEBREAK=CRLF,SQUEEZE=1.5,$
TYPE=TITLE, BORDER-BOTTOM=LIGHT,$
ENDSTYLE
ON TABLE PCHOLD FORMAT PDF
END
-EXIT

I may be missing something, but it appears that you're inserting a carriage return and line feed. If you don't want the extra line, take out the linefeed.

Using the LF should be sufficient as Darin said. Also note the stylesheet option of LINEBREAK='LF' that helps PDF output line breaks.

using style sheet option of 'LF' is helping me to break the data, but still I am getting extra lines under the title.

DEFINE FILE CAR
LF/A1 = HEXBYT(10, 'A1');
COUNTRYNAMECAR/A100= COUNTRY || LF || CAR || MODEL;
END
TABLE FILE CAR
PRINT COUNTRYNAMECAR
CAR
WHERE RECORDLIMIT EQ '10'
ON TABLE SET STYLE *
TYPE=REPORT, LINEBREAK=LF,SQUEEZE=1.5,$
TYPE=TITLE, BORDER-BOTTOM=LIGHT,$
ENDSTYLE
ON TABLE PCHOLD FORMAT PDF
END
-EXIT

See the Focal Point tips and techniques here for Kasi and Mickey's articles which will give you a solution.