1. create a stored procedure to delete or truncate the records of the particular table.
2. Use dbms_job package to schedule  it. ie, shcedule the stored procedure to be execute in a timely fashion, like midnight everyday or something like that.

set serveroutput on
declare
   l_job number;
begin
    dbms_job.submit( job => l_job,
                     what => 'delete zzz where col1 < 100;',
                     next_date => sysdate, 
                     interval => 'trunc(sysdate + 1) + 10/24 /* 10am daily */' );
    commit;
    dbms_output.put_line( ' your job is # '|| l_job);
end;
/