When we want to copy table from one Table to another new table

CREATE TABLE [dbo].[tblSubTaskSurveyEvalutaion]
(
	ActivityTd int not null,
	ID int IDENTITY(1,1) NOT NULL,
	ActivityName nvarchar(max) Null
	)
SET IDENTITY_INSERT tblSubTaskSurveyEvalutaion ON
	INSERT INTO tblSubTaskSurveyEvalutaion(ActivityId,ID,ActivityName)
 SELECT ActivityId,ID, ActivityName FROM tblSlippageSubActivity; 
SET IDENTITY_INSERT tblSubTaskSurveyEvalutaion OFF