WSO2 DSS supports batch requests, which takes of array of parameters as the input. What you need to do is create a dataservice enabling batch requests[1], with a simple insert query. Once it is deployed there will be a batch enabled request created from which you can insert multiple records. For more information you can tryout Batch Processing sample available inside DSS[2].
[1]http://docs.wso2.org/display/DSS310/Creating+Using+Various+Data+Sources
[2]http://docs.wso2.org/display/DSS310/Batch+Processing+Sample