Notice these are not the total number of events of myocarditis, but the number of events above the background rate. That's why it's called "additional events per million".
3 or 12 additional events of myocarditis after the first, 12 or 14 more additional events per million after the second shot, and 13 events following a third shot. On the low end that's 28 (39 on the high end) if you take 3 shots.
Compare that to your odds of myocarditis with covid, 7 incidents per million.
This means you're 4x (on the high end it's nearly 6x) more likely to get myocarditis from the vaccine. This is why my nephew will not receive the vaccine when he's old enough (turns 4 this year) and why I will not receive a booster.
"In males aged less than 40 years, we estimated an additional 3 (95%CI 1, 5) and 12 (95%CI 1, 13) myocarditis events per million in the 1-28 days following a first dose of BNT162b2 and mRNA-1273, respectively; an additional 14 (95%CI 8, 17), 12 (95%CI 1, 7) and 101 (95%CI 95, 104) myocarditis events following a second dose of ChAdOx1, BNT162b2 and mRNA-1273, respectively; and an additional 13 (95%CI 7, 15) myocarditis events following a third dose of BNT162b2 vaccine. This compares with 7 (95%CI 2, 11) additional myocarditis events in the 1-28 days following a positive SARS-CoV-2 test."
https://www.medrxiv.org/content/10.1101/2021.12.23.21268276v1.full.pdf