join and repeat value from a column of another table
Since the tables have no column in common, we'll have to use the rownum pseudocolumn which is asigned to every row in a resultset. Do not confuse with rowid which is hash-like and exists phisycally in the table. Since rowids go 1,2,3...n, they provide a way to join two unrelated tables.

select
    t1.c1,
    t2.c2
from
    (select rownum rn,c1 from a) t1 left join 
    (select rownum rn,c2 from b) t2 on (t1.rn=t2.rn)


NOTE:

I assumed A had more rows than B so I made a left join. You can turn things around should B have more rows than A.