add string varible to existing string in SQL Server

Your query should like below. Here it will check if table not exist then create table and insert one row to the table, if table already there then only the else part will execute and append the ',cherry' to the name everytime you execute the query.

SQL

IF  NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'Test1') AND type in (N'U'))
    BEGIN
        CREATE TABLE Test1(id INT, name VARCHAR(100))
        INSERT INTO Test1(id,name)VALUES(1,'apple')
    END
ELSE
    BEGIN
        UPDATE Test1
        SET name = name + ',cherry'
    END
SELECT * FROM Test1

Screenshot