The swell periods in the map graphics match quite well the swell periods in the table.
EA0B61A7-8EF0-4BD4-B2C7-5BB1184620D6.jpeg
Sometime there is a very small difference because the decimal is rounded in the graphic e.g. 9.3 is rounded 9s.
Another example:
https://community.windy.com/topic/9874/waves-and-swell/2