Convert Delimited Fields Into Distinct Permutation Records Linq

// Test class represents your test data:
private static void Main()
{
   //UPDATE: Corrected test data type
   //Test data
   DataTable dt = new DataTable();

   dt.Columns.AddRange(new []
   {
       new DataColumn("PassA",typeof(string)),
       new DataColumn("PassB",typeof(string)),
       new DataColumn("Other",typeof(string)), 
   });

   DataRow row = dt.NewRow();
     row["PassA"] = "1,2,3";
     row["PassB"] = "1,2";
     row["Other"] = "X";
     dt.Rows.Add(row);
   row = dt.NewRow();
     row["PassA"] = "1,3";
     row["PassB"] = "2";
     row["Other"] = "Y";
     dt.Rows.Add(row);

   var fullList =
       dt.Rows.Cast<DataRow>().Select(i => new
       {
          //First select turns the string into an array
          PassA = i["PassA"].ToString().Split(','),
          PassB = i["PassB"].ToString().Split(','),
          Other = i["Other"].ToString()
       })
       //The object is now IEnumerable<anon><string[],string[],string>>
       //We need to merge the two string arrays
       .SelectMany(i =>  //We make the first array the subject, but we still want to return all results, so selectmany

            i.PassA.SelectMany(  //Same logic as before, but we'll use an overload
                  a => i.PassB,  //second subject
                 (a, b) => new {a, b, i.Other})); //select our new object type
       //By the end we have a IEnumerable<anon<string,string,string>>

  //Output for checking
  fullList.ToList().ForEach(i =&gt;
  {
    Console.WriteLine("{0}\t{1}\t{2}",i.a,i.b,i.Other);
  });
}