Try this:
declare @Table table (col1 int, col2 int, col3 int)
insert @Table values (1, 2, 4)
select 'col1' as colname, col1 as colvalue
from @Table
union all
select 'col2' as colname, col2
from @Table
union all
select 'col3' as colname, col3
from @Table