Sintaks salah di dekat ')'. saat membuat tabel

autoincrement bukan kata kunci SQL Server. Saya pikir Anda berniat:

 string sqlStatement2 = "CREATE TABLE " + Table2Name + "" + 
                         "(line_id int not null identity(1, 1) PRIMARY KEY, " +
                          "line_full_name CHAR(50) NOT NULL," +
                          " network_id INTEGER FOREIGN KEY REFERENCES network(network_id))";

Selain itu, FOREIGN KEY memerlukan referensi tabel.