"A king of shreds and patches" is a phrase from William Shakespeare's play Cymbeline. It is spoken by Cloten, a foolish and arrogant character, who is describing himself. He is saying that he is a king of scraps and pieces, which suggests that he is not very wealthy or powerful. He is also saying that he is a king of chaos, which suggests that he is a troublemaker.
The phrase can be used more generally to describe someone who is in a state of disarray or who is not very well put together. It can also be used to describe someone who is a jack of all trades, but master of none.