UPDATE table SET value which SELECT from other table
So really these tables aren't related in any way at all. Assuming you want each row in table 2 assigned to a row in table 1, here's one arbitrary way to do it:

;WITH t1 AS 
(
  SELECT ID, col_1, rn = ROW_NUMBER() OVER (ORDER BY col_1)
    FROM dbo.table_1
    WHERE ID = 11 -- guessing here based on sample data
),
t2 AS 
(
  SELECT col_2, rn = ROW_NUMBER() OVER (ORDER BY col_2) 
    FROM dbo.table_2
)
UPDATE t1 
    SET col_1 = t2.col_2
  FROM t1 
  INNER JOIN t2 
    ON t1.rn = t2.rn;


If you have other columns you want to order by, you can add them. If you only want three rows and there are more than three rows in table 2, add:

WHERE t2.rn &lt;= 3;