is there a simple table representation of talks available somewhere?

https://pretalx.c3voc.de/rc3-2021/schedule/ is better.

Top right hand side has a well hidden pulldown to download .json, .ics etc

That's the same one as the linked table. It's not very usable on mobile phone browsers for example ...

On f-droid there's a dedicated Android app:

https://f-droid.org/packages/info.metadude.android.rc3.sched...