Unfortunately you can't currently change the layout of the TOC individually. You could try adjusting the font size for the book to see if that helps, but of course that will also affect the look of the rest of your book as well.
If you want a specific layout for your TOC, I have seen authors create a TOC in Canva or Book Brush and insert them as full page images for the print version.
Future updates will give you more customization options, but I'm not quite sure when that will be available.