First, both Tr and td expect an array reference as their second argument, not a list. Aesthetically, I'd also suggest using map instead of foreach in the loop. Put together,

#!/usr/local/bin/perl

use CGI qw/:standard/;

my @data = ([qw/x y z/], [qw/a b c/], [qw/1 2 3/]);
print
    header,
    table({-width=>200},
            [join '', (map Tr(map td($_), @$_), @data)]);
[download]

will give you what you want, I believe.

UPDATE

Whoops! I ignored my own advice. The above should work, but isn't too clear logically. This is what I was trying to do:

#!/usr/local/bin/perl

use CGI qw/:standard/;

my @data = ([qw/x y z/], [qw/a b c/], [qw/1 2 3/]);
print
    header,
    table({-width=>200,
           -border=>1},
            [Tr([map (td([map $_, @$_]), @data)])]);
[download]

Hope that helps.