Here is another way to it:

WITH CTE AS

(

SELECT

name as TableName,

object_id

FROM sys.tables WHERE schema_id = schema_id('dbo')

)

SELECT TableName,

CommaList = STUFF((

SELECT ',' + c.name

FROM sys.columns c

WHERE c.object_id = CTE.object_id

ORDER BY c.column_id

FOR XML PATH(''),TYPE).value('.','varchar(max)'),1,1,'')

FROM CTE

ORDER BY Tablename;