Bandai/Namco certainly do hold multiple registered trademarks on PAC-MAN, at least in Europe. They cover not just the video game side[1], but everything from kitchen appliances[2] to lotteries[3] and even beer[4].

[1] https://www.ipo.gov.uk/tmcase/Results/4/EU004977906

[2] https://www.ipo.gov.uk/tmcase/Results/4/EU000361600

[3] https://www.ipo.gov.uk/tmcase/Results/4/EU003574076

[4] https://www.ipo.gov.uk/tmcase/Results/4/EU008125031