Most efficient way to make multiple AJAX calls

I have an ASP.NET Core page where I need to display several charts using morris.js. This package renders the characts using client-side JavaScript.

Rather than building all the data for all the charts before the page is served, I’m thinking the page would feel more responsive if I serve the page and then use AJAX to get the data for each chart. But I’m a little unsure how well the JavaScript engine handles concurrency.

Is it okay to simply code one AJAX call after the other? Or would it be better to wait until each AJAX call finished before calling the next? I’d love to hear anyone’s thoughts who has some knowledge in this area.