Which platform an app will you be using?
I tablet like the Fire HD8 could be just fine for live streaming.
I think one of the most important aspect of livestreaming is a reliable Internet connection.
You need twice the upload speed that the planned stream speed..so I think you need 4G LTE or WiFi.
Depending of the content, you need good audio, since tablets (and phones) will pick all sort of sounds and background noises.
You might want to consider a external mic.