Robert Penny, 30, flew into a rage after being head-butted during a fracas at the West Riding pub on Castle Road.
After hurling a pint glass at his assailant, Penny picked up balls from the pool table and began throwing them like missiles towards punters in the bar, York Crown Court heard.
One of the pool balls struck a man in the face and a woman was hit on the arm, said prosecutor Nicholas Rooke.
“He picks up another two balls (and throws them) into a crowd of people in the pub,” added the barrister.
Some in the crowd were cowering in the corner of the bar as staff and punters tried to calm Penny down and usher him away.
“The defendant was looking for more balls to throw, then picks up a stool,” said Mr Rooke. “People were pleading with him to stop.”
The court heard that Penny had been in “high spirits” before the incident, “play-fighting with his friend and behaving in an innocent way”.
But he lost his rag after being attacked by a punter and allegedly threw a pint glass towards the man, before punching him in the face.
Penny was arrested at the scene and charged with affray. He admitted the offence on the basis that had not thrown a glass, only its contents, and appeared for sentence on Friday.
The court was shown CCTV footage of the incident which happened at about 6.20pm on April 28 last year.
“There were at least 30-plus people in the bar and (the incident) clearly caused them mush distress,” said Mr Rooke.
“Numerous people can be seen running from the pub and diving out of the way while the pool balls are being thrown.”
Penny, of Westway, Eastfield, had drunk eight pints during a six-hour bender and told officers he couldn’t recall much of the incident.
He had a track record for violence, with previous convictions for assault occasioning actual bodily harm, criminal damage, being drunk and disorderly and obstructing a police officer. He had been barred from pubs in Scarborough in the past.
Defence barrister Taryn Turner said although Penny was drunk, he was not the instigator of the violence in April.
She conceded that he had behaved “appallingly” but was “instantly remorseful (and) very ashamed”.
Judge Andrew Stubbs QC said the CCTV footage showed Penny to be “out of control, repeatedly arming himself with missiles and throwing them as hard as he could towards a group of people”.
“You completely lost your self-control”, he told Penny. “I have no doubt that you are very sorry, but similarly I have no doubt that this was not out of character (due to) your previous convictions.”
Mr Stubbs said such violence could only be met with an immediate prison term.