Rural Jobs and Investment Act of 2018 This bill amends the Consolidated Farm and Rural Development Act to establish a Department of Agriculture (USDA) grant program for establishing jobs accelerators that are located in or serve low-income rural communities. The jobs accelerators are centers or programs that may provide co-working space, in-demand skills training, entrepreneurship support, and other specified services. USDA must establish an interagency federal task force to support the network of jobs accelerators by providing certain information, technical assistance, support services, and opportunities for collaboration. The bill also reauthorizes and modifies the USDA Rural Business Investment Program. The modifications address the limitation on rural business and investment companies controlled by Farm Credit System institutions and coordination with the Small Business Administration Small Business Investment Company program.