Tablet reboots on its own?

I bought a huawei media pad m5 lite on Monday.

Today I noticed 2 times that the tablet restarts when I touch the charging cable (I accidentally came to the charging cable 2 times while cleaning up).

yesterday I probably had the problem (with a different cable). When I looked at the tablet it had restarted, but actually put it on an update.

What else could be the reason?

I have exactly the same tablet, it is not normal. Maybe you go to the shop where you bought it and describe your problem there.