There is no plugin in C2 thar has a builtin editor that does that. There are tools to do it and create a json string that you can load into the array object.
* There are a few free capx on the forum that do it.
* A few sold in the store.
* You can make the spreadsheet in excel and export it as a comma seperated value (cvs) file. Then you can load that into an array either by doing it yourself with a loop and the tokenat() expression or using a plugin made to parse the file.