DECLARE @DataSeries VARCHAR(MAX);
SELECT TOP 10 
	@DataSeries = ISNULL(@DataSeries + ' | ', '') + CONVERT(VARCHAR(100) , [Name])
FROM Production.Product;

SELECT 
	[ProductCategoryID],
	[Name],
	STUFF
	(
		(
			SELECT TOP 5 ' | ' + [Name] 
			FROM Production.Product
			WHERE Production.Product.ProductSubcategoryID = Production.ProductCategory.ProductCategoryID
			FOR XML PATH ('')
		), 1, 2, ''
	) AS [TopProducts]
FROM Production.ProductCategory