var luggage = [‘пакет’, ‘мяч’, ‘тапки’, ‘когтеточка’, ‘коробка’, ‘миска’, ‘мята’];
var startIndex = 2;
var quantity = 3;
var chosenLuggage = [];
for( var i = startIndex ; i < startIndex + quantity; i++) {
chosenLuggage.push(luggage[i]);
console.log(chosenLuggage)
}