Agh, I didn't read the question fully. The following answers the question for the anime series - not the manga:
Not much. It's hard to definitively say how much, but let's give it a go based on the CrunchyRoll descriptions. Because they're so short, they're pretty comprehensive of what happens.
This will be a reasonably loose attempt at collation - the actual times they play an entire game is much less.
Season 1 (5/12):
- Teaching Yuri how to play tennis is harder than herding cats. YES
- Takamiya Nasuna has returned to play tennis, but first they have to harvest the court. YES
- Bando Marimo means well, but she has a soul of an old man… a perverted old man
- Kanae has invited the club to her house... things get awkward from here.
- All jokes aside, Nasuno decides to get serious and play at her full strength! YES
- The girls enjoy a day at the pool by themselves.
- The club needs new members! YES
- Nasuno wants to create something "special" for her father's birthday.
- Marimo gets a... job?
- The showers at school are broken so the club visit the public baths.
- Let’s go to a festival!
- The club is finally back to practicing but when they lose their only ball… YES
Season 2 (4/12):
- The four members of tennis club are asked to help with a bean throwing event by Kanae's cousin, who works at a nursery school. Concerned the children are frightened of her, Marimo receives advice from the principal, but...
- Kondo-san from the newspaper clubs asks to interview the tennis club. Can the excited upperclassmen properly show off the activities of the tennis club?! YES
- At Nasuno's suggestion, the four girls go on an overnight trip together. However, as expected, there's something strange about the method of transportation and lodging arranged by Nasuno...
- After finishing practice on their overnight trip and recharging themselves in the bath, the four girls hold a hot springs table tennis tournament. How will the gradually escalating battle end? YES
- On the final day of their trip, the tourist spot the manager told the girls about turns out to be a silver mine! And what event occurs on the bus on their way home...?
- When Nasuno suddenly declares she wants a pet, she and the other members head to the pet store where they find unbelievable animals!
- The day of the sports festival has arrived. Having entered a club relay race, the members come together to try to win, but...
- When Kanae becomes upset over her short stature, Nasuno takes her to a ranch. Will milking a cow make her taller!?
- One day, the four girls take on the base ball club with their right to use the tennis court on the line. Certain character appears to fill their roster, turning it into a white hot battle! YES
- At the bottom of the first inning with bases loaded and two outs, batter Kanae breaks out a certain pose! And finally, the conclusion! YES
- One night, a mysterious flying object crash lands at Marimo's house. From the dazzlingly bright light appears an alien who calls himself "Tomalin!"
- Kanae and Yuri go to an udon restaurant with coupons they received from Kondo-san. However, there's nothing ordinary about this udon restaurant!
Season 3 (3/12):
- Nasuno-senpai takes everyone skiing. On what kind of course did the four skiing beginners end up?!
- When it starts pouring rain, everyone seeks shelter at Kanae's house. On their way home, Kanae is struck by a bolt of lightning and uses her superpower "Kana Kana Wave"...
- Nasuno is saved from a group of seemingly terrifying hooligans by a high school student named Yota. However, another group of assassins appears!
- At the suggestion of a long-haired Nasuno and short-haired Kanae, Yuri accompanies them to a salon. What NEW hairstyles does she see during her trip?!
- The group heads to the shrine for their first visit of the New Year. After drinking some amazake, Yuri runs out of control and things turn dire!?
- Nasuno's bakery is 300 million yen in debt?! The girls try coming up with a new menu for the reconstruction of the store, but...
- A story of Yuri as a third year middle school student. After making it into Kameido High School, Yuri tries to join the tennis team, but... YES
- When Kanae's strings break the gang heads to a tennis supply store. The store stocks nothing but unusual strings. Which strings will Kanae choose? YES
- Yuri encounters the lingering spirit of her uncle at his funeral. Somehow her uncle takes control of her body, and...
- While Marimo is playing games at home, she is suddenly sucked into the game world through her TV. Will Marimo make it safely back to her own world?
- The national tennis tournament has begun! What secret strategy does Kanae use against the formidable Usagikame High?! YES
- The fearsome final exams are approaching. The girls gather at Kanae's house to study.
There is 7 seasons of this and also 11 tankobans - so I think I will stop before I waste my entire evening - but I think it's clear that the majority ( > 50% ) of time is spent on non-tennis-related items.
