“Turn to your neighbor” is an often-used technique presenters rely on for “audience involvement.” Personally, especially today, I think it has passed its prime. Instead, how about, “When I give you the signal, I want you to get up and find two other people you don’t know and form a group of three away from the tables. Ready? Go!” Yes, this chaotic madness is noisy, disorganized for a few moments, but terribly fun.
Next interaction can be “new groups of two” and then “take your group of two and join another group of two to become a group of four” and so on. Get people together to meet, get them away from the tables (I never use any tables…they just get in the way) and let them talk to one another.
Yes, what you have to say is important, but just not that important. Consider being a presenter/facilitator vs. a main presenter. Consider ‘lecturettes’ instead of a 90-mintue talk. Speak for 8-12 minutes then get them talking to one another! They may have initially come to hear you; they will remember having been able to talk and meet one another. Yes your expertise is valuable and so is the experience they had that you allowed.