Evening. I am part of a small eclectic group that is newly formed. I just posted a topic and it struck me as odd that, even though our membership is small (21) there were within five minutes of me placing my thoughts into a forum, eleven views. Does this mean that anyone can read into an invite only group every new essay?

It depends on your forum characteristics. Is your forum public? If it is, everybody can read, but only members can write there.

It is private, invite only.

No, no. Your group maybe private (invite only), but you have to set your forum to private or public (in Edit settings). If the forum is public then everybody can read the posts.

don't forget the other members will get a notification that there is new content in the group and may go straight away to view it