Luckily there is a way around this. Captivate can import HTML5 to embed into a slide by clicking on Media and then selecting "HTML5 Animation".
Now this was originally intended for HTML5 animations of course but luckily Captivate doesn't care what the HTML is you import, as long as it's zipped up. So you can create your tables in HTML and import them that way. I was so relieved when I found out you could do this, I was working on a Nutrition Consultant course at the time which needed a lot of tables!
One important thing to remember is to make your HTML responsive (as you are making your course mobile friendly right?) It isn't hard to do, you just need to add a CSS media query in the HTML to make sure all your font sizes match Captivate. You can find out how to do media queries here.