Advice on adding content

I have set up a website for a journalist who has a backlog of articles which have been published over several years. He would like to add these to his website.

There is currently a page of posts for these articles which can be entered manually. But there are something like 500 previous articles, which would obviously take a considerable time to enter individually.

Can anyone advise if there is any way to import these into a WordPress site as posts, or perhaps recommend a plug-in to handle a series of short articles?

Any help appreciated.
Mike