I have a tablet and I don't intend to use it for calls and texting. The text at the top saying "emergency calls only" is annoying and distracting, is there no way to hide it without having to install a SIM card?
That is rather odd. Without any kind of SIM in (working or not) that message shouldn't show as you can't make calls without a SIM inserted. You can try inserting a non-working SIM (no service) into the device and see if that stops it.
However, to be honest, it seems more like a software flaw. I would contact the manufacturer about it.