Here are the options:
1. You can use small numberpad type for that category by changing numerator type to small from category settings (edit category on menu settings). So you'll be able to decrease column numbers.
2. You can modify button headers for multiple lines. Click "Edit Product Properties" and on "Header" column add
\r to break a button header to multiple lines. For example [/b]Hot\rSandwich[/b] will displayed in two lines. If you want to do it for all button headers you enable "Wrap Text" setting for a Menu Category.
3. By increasing the Page Count of that category you can break that category to multiple pages.
4. Visit this link
http://sambapos.org/en/content/sambapos-252-test-release for sub-category feature.
Please share the result with us.
Thanks