posts.js

const fetch = require('node-fetch');

let posts = [];
let postsPromise = fetch('https://jsonplaceholder.typicode.com/posts')
    .then(resp => resp.json())
    .then(data => {
      posts = data.slice(5,15);
    });

let users = {};
let usersPromise = fetch('https://jsonplaceholder.typicode.com/users')
    .then(resp => resp.json())
    .then(data => {
      users = data.reduce((p, c) => {
        p[c.id] = c;
        return p;
      }, {});
    });

Promise
  .all([postsPromise, usersPromise])
  .then(responses => {
    //    console.log(posts, users);
    let table = posts.map(e => {
      return {
        author: users[e.userId].name,
        website: users[e.userId].website,
        title: e.title
      };
    });
    console.log(table);
  });