use Modern::Perl;
use Data::Dump qw/dump/;

my %heights;

while (<DATA>) {
    push @{$heights{$1}}, $3 if /set\s+height\s+"([^"]+)"\s*("([^"]+)")?/;
}
say dump(%heights);

__DATA__
set height "house"
set height "house" "5 meter"
set height "house" "10 yards"
set height "table" "80 cm"
set height "table" "30 inch"