Análise de variável dinâmica MS SQL incorretamente

1. Use os tipos corretos SYSNAME para identificadores, NVARCHAR(MAX) para consulta
2. Usar REPLACE em vez de concatenar, será muito mais fácil depurar, especialmente quando você precisar de literais de string
3. Considere usar QUOTENAME função

DECLARE 
    @tableName  SYSNAME,
    @columnName SYSNAME,
    @prompt     VARCHAR(20),
    @dynSQL     NVARCHAR(MAX);

SET @tableName  = QUOTENAME('A1-ExciseESN');
SET @columnName = QUOTENAME('Anode Excise ESN (A1)');

SET @dynSQL = 
N'INSERT INTO  <tableName> 
 ([trav num], <columnName>)
Select [trav num], <columnName>
FROM [temprmi$] t1
PIVOT(min([Lvl1 Trace Data])
FOR [Prompt Text] IN (<columnName>)
   ) AS PVTTable
     where <columnName> is not null 
        and [trav num] not in (select [trav num] from <tableName> )'

SET @dynSQL = REPLACE(REPLACE(@dynSQL, '<tableName>', @tableName),
               '<columnName>', @columnName);

PRINT @dynSQL;

INSERT INTO  [A1-ExciseESN] 
 ([trav num], [Anode Excise ESN (A1)])
Select [trav num], [Anode Excise ESN (A1)]
FROM [temprmi$] t1
PIVOT(min([Lvl1 Trace Data])
FOR [Prompt Text] IN ([Anode Excise ESN (A1)])
   ) AS PVTTable
     where [Anode Excise ESN (A1)] is not null 
       and [trav num] not in (select [trav num] from [A1-ExciseESN] )