let objGoods = {
    "ручка": [100, 50.60],
    "карандаш": [120, 30.00],
    "тетрадь": [200, 10.50]
};

outArr = [];
Object.entries(objGoods).forEach((entry) => {
    let name = entry[0];
    entry[1].forEach(price => {
        outArr.push({ "name": name, amount: price })
    })
});

console.log(outArr);