DECLARE

 l_sql varchar2(150);
 
 cursor tablelist is 
 select table_name from dba_tables where owner = 'ME';
 

 tabs tablelist%rowtype;
 n_rowcnt number;
 
Begin
 open tablelist;
      loop
          fetch tablelist into tabs;
          exit when tablelist%notfound;
          
          l_sql := 'select count(*) ROW_COUNT from '||tabs||' ;';
          
          n_rowcnt := l_sql;       
          dbms_output.put_line(tabs,n_rowcnt);
      end loop;
 close tablelist;
end;

DECLARE

  l_sql varchar2(150);
 
  cursor tablelist is 
    select table_name from user_tables; -- where owner = 'ME';
 
  tabs user_tables.table_name%type;

  n_rowcnt number;
 
Begin
  open tablelist;
    loop
       fetch tablelist into tabs;
       exit when tablelist%notfound;
          
       l_sql := 'select count(*) ROW_COUNT from '||tabs;

       execute immediate l_sql into n_rowcnt;
       dbms_output.put_line(tabs||' '||n_rowcnt);
     end loop;
  close tablelist;
end;
/

SCOTT> select table_name,
  2         to_number(extractvalue(
  3                     dbms_xmlgen.getXMLtype ('select count(*) cnt from '||table_name),
  4                     '/ROWSET/ROW/CNT')) rows_in_table
  5  from user_tables
  6  where tablespace_name is not null or partitioned='YES' 
  7  order by 1
  8  /
TABLE_NAME                     ROWS_IN_TABLE
------------------------------ -------------
BONUS                                      0
DEPT                                       4
EMP                                       14
SALGRADE                                   5

4 rows selected.