Easy way to create object repository of API when API request has nearly 100 variables

@ Zarashima,
I want to automate the API response. It is easy to do data driven automation of API when there are nearly 25 variables in request API.
But now i want to do data driven automation of API when there are nearly 100 variables in request API.
I need to create nearly 100 variables in object repository for that.
Similarly need to create nearly 100 variables in Testcase and also in Excel sheet for that.
I am interested to know is there any easy way to create those 100 variables in object repository, Testcase and also in Excel sheet.