>Suppose I have a table A with 100 records and Table B with 25 Records. I want to insert the
>records of Table B in Table A, after 75 records of Table A.
>I.e First 75 recodrs shoud be of A , next 25 of B and than 25 of A. How it will be done ?


Several ways. I think you want a SQL solution? Something like (untested) this if tablea and tableb have the same structure:

SELECT * ;
    FROM tablea ;
    WHERE RECNO() <= 75 ;
UNION ;
SELECT * ;
    FROM tableb ;
    WHERE RECNO() <= 25 ;
UNION ;
SELECT * ;
    FROM tablea ;
    WHERE BETWEEN(RECNO(), 76, 100) ;
    INTO TABLE result.dbf