Examples of Applied Micro Paper with R (!) Code and Data in Public Repository
You could try searching the Harvard Dataverse for fileType:"R Data" like this: https://dataverse.harvard.edu/dataverse/harvard?q=fileType%3A%22R+Data%22



I think your use case of wanting to search for data in specific formats such as RData is a common one so I just created an issue about improving Dataverse to support this use case better: https://github.com/IQSS/dataverse/issues/2707