District-based Social Tables, an upstart that makes software for event organizers, has attracted money from local investors, including $1 million in fresh capital and $600,000 in converted debt, executives plan to announce this week.

The round was led by Lansdowne-based Militello Capital. Existing investors, including 500 Startups and Fortify Ventures, also contributed.

The young firm has expanded to 18 employees from four in the past year, adding more developers as well as a team of sales and marketing people. The software has also evolved significantly in that time.

What began as an way for event hosts to create basic seating charts online now provides venues large and small with a three-dimensional rendering of their space. The company tallies some 500 customers, including the Ronald Reagan Building and International Trade Center, Georgetown University, the State Department and the U.S. Holocaust Memorial Museum, locally.

Expanding the software “all started with experimentation and being nimble and being able to build as fast as people made requests,” founder and chief executive Dan Berger said.

Organizers can now create a floor plan that includes tables, podiums and stages and generate an inventory of the equipment an event will require. Caterers can also use Social Tables to identify which attendees require special food accommodations and determine how their servers will move about the room.

Berger said Social Table’s customers not only use the software to plan and orchestrate existing events, but to attract new business by creating models for what a future event might look like.

“If you’re a hotel or venue, you can use our software to sell because people can visualize their event,” he said. “You get a complete 3-D rendering of the entire event.”

Bits and bytes

District-based marketing software company TrackMaven added industry veteran Joe Payne to its board of directors last week. Payne is the former chief executive of Eloqua, the Vienna-based software company that Oracle bought for $871 million in December.

Silver Spring-based MobileSpaces funneled $8.6 million from Marker and Accel Partners into its coffers last week as the mobile security upstart looks to expand its sales and marketing staff, according to a news release.

The company’s technology secures the mobile applications that have helped make smartphones so popular. It’s used on 1.5 million apps for businesses on both iPhone and Android devices, according to its Web site.