@a = ( [1, 2.3 ], ['a'..'c'], ['p'..'r']);;
pp \@a;;

[[1, "2.3"], ["a", "b", "c"], ["p", "q", "r"]]

push @{ $a[ 1 ] }, 'a scalar';;
pp \@a;;

[[1, "2.3"], ["a", "b", "c", "a scalar"], ["p", "q", "r"]]