Hi and welcome to Android Forums!
If understand you correctly, your tablet had no battery installed? And you had it on the charger for what reason? The battery indicator was likely an alert warning you that there was no battery to charge; and if you remove the power cord with no battery in it, then of course it won't turn on any more than any other unplugged device will. The tablet MUST have power: either from the power cord or a battery.
I may have you completely misunderstood here and I hope I do. I have never heard of a tablet without a battery in it. You will have no choice but to use it with the power cord connected at all times until a battery is installed.
I hope this helps.
It’s great to have you here
