This would be useful in condition like you need to perform some operation on DataTable using LINQ and get back result into another 'DataTable'. Means, you can filter and projection on one DataTable and get result in another DataTable.
We can achieve this by using 'CopyToDataTable' method of LINQ query result variable.
Here is example for this.
In this example we are taking one DataTable which contains product information like ID, name, etc. Now we get only those products which ID is greater than one by LINQ operation on this table and get result in another table using 'CopyToDataTable' method of LINQ query result variable.