Some charts and tables come with some kind of built in title but they're not accurately descriptive enough. Also, there are no axis labels for charts which makes some of them confusing to read if you didn't necessarily make the chart yourself.
This is possible today. Click the "Format chart" icon in the green right corner which will open the Chart editor. On the Customize tab, you'll find options to customize the chart title, axes and more.
I'm still confused as to how to edit/title pivot tables.