sending three arrays over json

They are strings that are coming out of three separate tables. I was thinking a 2 d array since I need to keep them separate for use on the client side. so $PR= ["go shopping", "get gas", "wash windows"]
 and    $AC= ["bake bread", "juliane carrots"]

                                   columns
index
0             "go shopping"            "bake bread"
1                "get gas"              "juliane carrots"
2               "wash windows"


So I know that in a zero based system column 0 is for homemaint and I know column 1 is for cooking

array[1][1] = "juliene carrots"

This was a basic data structure 30 years ago when I went to school. Is it not so easy in PHP? I tried to push them onto a list with push_array() but I am not sure there are two d arrays in php. Is there an easier way to do it?

proof that an old dog can learn new tricks