My tablet shut off and it won't turn back on

I laid down my tablet to go into another room for around 5-10 minutes. It had 53% charge left on it. It had turned off on it's own and I can't turn it back on. I've tried the 8 second hold to turn on and that didn't help. I now have it plugged in and I noticed the blue light at the plug site is normally on when charging. Now, instead, the blue light is blinking and I've never seen it do that before. I'm on my old RCA tablet to report this. I got the RCA Viking Pro II tablet that is having problems which I purchased the end of November. What does the flashing blue light mean? How can I turn it on. Thank you!