Multichannel On Site Fellowship
Think regular events like Wednesday suppers, and one-off events like dances and Super Bowl parties.
Regular events begin to shape the rhythm of people's lives. One-off events reach out to new constituencies and encourage members to bring friends.
These activities exist for their own sake. They don't necessarily feed people into Sunday worship. They don't necessarily lead to formally joining the congregation. They are "touches," ways for the congregation to have a positive and Godly impact on people's lives.
What a congregation offers will depend on needs and schedules in its community. Don't just ask members what they want, but look at the larger community, your "mission field," and see what needs you can meet.
In the years after World War Two, for example, when Americans were suddenly and radically uprooted, church suppers provided valuable socialization. That need faded in the 1960s and beyond, as many moved to suburbs and found different avenues to socialization or pulled inside.
Nowadays, in many urban and suburban communities, a fresh need for socialization has emerged, this time in contexts of significant diversity, issues of trust, young adults looking for connections outside work colleagues, as well as frustration with the loneliness of stay-at-home anonymity.
It is unlikely that one midweek supper, like the "Wednesday church night" of old, will serve all needs. The effective congregation will offer multiple fellowship activities, at least some of them targeted to niche subsets. All will require careful marketing that explains each event (no assuming that "everyone knows"), who is welcome, and details on food and child care.
What about cost? The typical parish is struggling financially and can't simply provide food for everyone. Try carry-in food, bring-a-sandwich-to-share and and a small donation for supplies and beverages. Be sure to provide child care, but let parents chip in to pay for it.