Reconfigurable intelligent surfaces (RIS) are a core component considered in sixth generation (6G) communications. By utilizing an RIS prototype system in the 5 GHz band, this paper provides a comprehensive dataset of S21 channel measurements of various geometric arrangements of antennas and RIS. The dataset is provided in full on IEEE DataPort. Additionally, the in-detail documentation of the measurement setup, location, devices, geometries, and algorithms is available on GitHub.