a polite phrase meaning 'as you know' or 'as you are aware', used to introduce or remind the listener of something they are presumed to know.
ご存知の通り、来週は本社から役員が来日します。
As you know, executives from headquarters will visit next week.
ご存知の通り、このプロジェクトは予算が限られています。
As you know, this project has a limited budget.
ご存知の通り、彼は現在病気療養中ですので会議には出席できません。
As you know, he is currently on medical leave and cannot attend the meeting.