Why is my Sqlite table doubling it's self?

My Sqlite table should have 50 rows. When I run the program for the first time, and go to check the table through firefox viewer, I see 50 rows (as it should be).

When I run the program for a second time and check the table, it's rows double - i,e it now has 100 rows. (This is the problem)

Ive had suggestions to use DELETE from, but I dont want to delete the table, as I want to see it in the firefox viewer after I run the program for debugging purposes.

 // We use these three SQLite objects:
          SQLiteConnection sqlite_conn;
          SQLiteCommand sqlite_cmd;

          // create a new database connection: 
          sqlite_conn = new SQLiteConnection(@"Data Source=database.db;Version=3;");

          // open the connection:
          sqlite_conn.Open();

          // create a new SQL command:
          sqlite_cmd = sqlite_conn.CreateCommand();

          // Let the SQLiteCommand object know our SQL-Query:
          sqlite_cmd.CommandText = "CREATE TABLE IF NOT EXISTS 'tab1' (Seq text, Field text, Desc text, Len text, Dec text, Typ text, Percnt text, Pop text, Alzero text, MaxLen text );";

          // Now lets execute the SQL                                                                                 
          sqlite_cmd.ExecuteNonQuery();

          // **** SQLITE TRANSFER SECTION 1 - transfer values from list to table *****

          sqlite_cmd.CommandText = "INSERT INTO tab1 (Seq, Field, Desc, Len, Dec, Typ, Percnt, Pop, Alzero, MaxLen) VALUES (@p1, @p2, @p3, @p4, @p5, @p6, @p7, @p8, @p9, @p10)";
          sqlite_cmd.Parameters.AddWithValue("@p1", 6);  // dummy initial values 
          sqlite_cmd.Parameters.AddWithValue("@p2", 878); 
          sqlite_cmd.Parameters.AddWithValue("@p3", 56);
          sqlite_cmd.Parameters.AddWithValue("@p4", 6);
          sqlite_cmd.Parameters.AddWithValue("@p5", 546);
          sqlite_cmd.Parameters.AddWithValue("@p6", 565);
          sqlite_cmd.Parameters.AddWithValue("@p7", 568);
          sqlite_cmd.Parameters.AddWithValue("@p8", 526);
          sqlite_cmd.Parameters.AddWithValue("@p9", 586);
          sqlite_cmd.Parameters.AddWithValue("@p10", 526);


          for (int i = 0; i < NumListValues; i += 10) // Filling SQlite table rows and columns with values from our list 
          {

              sqlite_cmd.Parameters.AddWithValue("@p1", list[i]);
              sqlite_cmd.Parameters.AddWithValue("@p2", list[i+1]);
              sqlite_cmd.Parameters.AddWithValue("@p3", list[i+2]);
              sqlite_cmd.Parameters.AddWithValue("@p4", list[i+3]);
              sqlite_cmd.Parameters.AddWithValue("@p5", list[i+4]);
              if (i > 490)
                  break; 
              sqlite_cmd.Parameters.AddWithValue("@p6", list[i+5]);
              sqlite_cmd.Parameters.AddWithValue("@p7", list[i+6]);
              sqlite_cmd.Parameters.AddWithValue("@p8", list[i+7]);
              sqlite_cmd.Parameters.AddWithValue("@p9", list[i+8]);
              sqlite_cmd.Parameters.AddWithValue("@p10", list[i+9]);
              sqlite_cmd.ExecuteNonQuery();

          }