USE tempdb;

CREATE TABLE dbo.persNNAppMovCtra(
nnr_numcontr int NOT NULL,
nnr_rinnid int NOT NULL,
nnr_codart varchar(18) NOT NULL,
pnr_codtchi smallint NULL);

CREATE TABLE dbo.persContrattiXChiamate(
nnr_numcontr int NOT NULL,
nnr_rinnid int NOT NULL,
nnr_codart varchar(18) NULL,
pnr_codtchi smallint NULL,
nnr_codart2 varchar(18) NULL,
pnr_codtchi2 smallint NULL,
nnr_codart3 varchar(18) NULL,
pnr_codtchi3 smallint NULL,
nnr_codart4 varchar(18) NULL,
pnr_codtchi4 smallint NULL
);

INSERT dbo.persNNAppMovCtra VALUES(1, 1, 'P010', 10); 
INSERT dbo.persNNAppMovCtra VALUES(1, 1, 'P020', 15); 
INSERT dbo.persNNAppMovCtra VALUES(1, 1, 'P030', 20); 
INSERT dbo.persNNAppMovCtra VALUES(1, 1, 'P032', 10); 
INSERT dbo.persNNAppMovCtra VALUES(1, 2, 'P035', 500); 
INSERT dbo.persNNAppMovCtra VALUES(2, 1, 'P012', 25); 
INSERT dbo.persNNAppMovCtra VALUES(2, 1, 'P020', 20); 
INSERT dbo.persNNAppMovCtra VALUES(2, 1, 'P032', 15); 

WITH CTE_Data AS
(
    SELECT *, ROW_NUMBER() OVER(PARTITION BY nnr_numcontr, nnr_rinnid ORDER BY nnr_numcontr) AS Col
    FROM dbo.persNNAppMovCtra
)
INSERT dbo.persContrattiXChiamate
SELECT
      nnr_numcontr
    , nnr_rinnid
    , MAX(CASE Col
        WHEN 1 THEN nnr_codart
        ELSE NULL
      END) AS C1
    , MAX(CASE Col
        WHEN 1 THEN pnr_codtchi
        ELSE NULL
      END) AS C2
    , MAX(CASE Col
        WHEN 2 THEN nnr_codart
        ELSE NULL
      END) AS C3
    , MAX(CASE Col
        WHEN 2 THEN pnr_codtchi
        ELSE NULL
      END) AS C4
    , MAX(CASE Col
        WHEN 3 THEN nnr_codart
        ELSE NULL
      END) AS C5
    , MAX(CASE Col
        WHEN 3 THEN pnr_codtchi
        ELSE NULL
      END) AS C6
    , MAX(CASE Col
        WHEN 4 THEN nnr_codart
        ELSE NULL
      END) AS C7
    , MAX(CASE Col
        WHEN 4 THEN pnr_codtchi
        ELSE NULL
      END) AS C8
FROM CTE_Data
GROUP BY nnr_numcontr, nnr_rinnid
ORDER BY nnr_numcontr, nnr_rinnid;

SELECT *
FROM dbo.persContrattiXChiamate;

/* Output:

nnr_numcontr nnr_rinnid  nnr_codart         pnr_codtchi nnr_codart2        pnr_codtchi2 nnr_codart3        pnr_codtchi3 nnr_codart4        pnr_codtchi4
------------ ----------- ------------------ ----------- ------------------ ------------ ------------------ ------------ ------------------ ------------
1            1           P010               10          P020               15           P030               20           P032               10
1            2           P035               500         NULL               NULL         NULL               NULL         NULL               NULL
2            1           P012               25          P020               20           P032               15           NULL               NULL

(3 row(s) affected)

*/

DROP TABLE dbo.persNNAppMovCtra, dbo.persContrattiXChiamate;