I am having the same issue. I have an invite list of 68 people and nowhere to put them! So far, I have come up with Morgan Run CC, The Prado, Burlap, Vin De Syrah, and Pacifica in Del Mar. I would love to be more cost effective and go to a park but then there is the issue of renting tables and chairs....
Re: Baby Shower Locations
Apparently you can check up even this on Yelp: https://bit.ly/w95B4n.
Doesn't work perfectly (baby back ribs shows up and that's just wrong), but some of the comments on past baby shower attendees were helpful!