From Sys:

SQL> grant analyze any to siam;  [For granting exec dbms_stats.flush_database_monitoring_info to other user]

 

SQL>conn siam/siam;

SQL> create table mon(a number,b varchar2(100));

 

SQL> select monitoring from user_tables where table_name='MON';

 

In 10g table automatically has monitor option enabled.
For 9i you should execute the following:

SQL> alter table mon monitoring;

SQL> insert into mon values(1,'a');

SQL> insert into mon values(2,'b');

SQL> insert into mon values(3,'c');

SQL> commit;

SQL> select * from user_tab_modifications where table_name='MON';

SQL> exec dbms_stats.flush_database_monitoring_info;

SQL> select * from user_tab_modifications where table_name='MON';

SQL> delete from mon where a=3;

SQL> select * from user_tab_modifications where table_name='MON';

SQL> exec dbms_stats.flush_database_monitoring_info;