There are a few threads that cover how to do this if you haven’t found it already. There is a search box on the right hand side of the main forum pages to search the forums if you need to in the future.
I’ll copy/paste from this thread – https://appfinite.com/topic/how-to-centered-the-price-table/#post-11320
“The pricing table was originally designed for 4 tables, so if you only need 3, then you could adjust the width of them all so it stretches to each end.
Look on line 726 in your css and change the width to around 33% or so until you get the width you want –
.plan-col,
.plan-col-popular {
width: 33%;
}
Although that line number may be different for your theme/site. Just search your style.css for the “Plans” section and you’ll see what I’m referring to.