multiTable.js

const $ = id => document.querySelector(id)

function init() {
    const fruits = ['Apple', 'Peach', 'Banana']
    window.addEventListener('load', () => {
        // main(fruits)
        multTable(9)
    })
}

function main(fruits) {
    let li = null
    fruits.forEach(fruit => {
        li  = document.createElement('li')
        li.appendChild(document.createTextNode(fruit))
        $('#fruits_list').appendChild(li)        
    })
}
init()


function multTable(n) {
    let table = []
    for (let i = 0, cols; i < n ; i+=1) {
        cols = []
        for (let j = 0; j < n; j+=1) {
            cols.push((i + 1) * (j + 1))
        }
        table.push(cols.join(','))
    }
    console.log(table.join('\n'))
}