Meatless Mondays? How about a big-time meatless meetup? That would be VegFest 2013, billed as the country’s largest vegetarian festival, on Saturday and Sunday at the Seattle Center Exhibition Hall. The goal is to bring in the veg-curious as well as the committed, with hundreds of food booths in a “sampling extravaganza” from vegan seafood to dairy-free cheese, as well as cooking demos and discussions on health. Cost: $8, or free for ages 12 and younger.