It seems you want to build a report rather than a table. For that, there many other procs that is more suitable (summary, tabulate, report etc).
But, if you want to do it in one sql statement, you could use the above example, and linking the two queries together with a outer union corr:
create table sumtable as
select product, sum(amt1) as Expr1,sum(amt2) as Expr2
from data
group by product
outer union corr
select "Total" as product, sum(amt1) as Expr1, sum(Amt2) as Expr2
from data;
Whether this is one or two sql statements I think is just a matter of semantics.
/Linus
Data never sleeps