Does there even have to be a tablet section? Google Play does not have different sections for phones and tablets. As far as I know, there are only two differences between the Jolla phone and tablet:

1. Screen size (including a landscape support). If you write your app in a way that is not screen size and orientation agnostic, then you are a rubbish developer and get what you deserve.
2. CPU architecture. I say, just build your app for ARM or x86 and upload accordingly. The device will choose whichever one is appropriate.