Yes, you can save arrays with other collection types inside - other arrays, tuples, dictionaries, objects, etc. Just one example for a playground:
import Foundation
let a: [Int] = [1,2,3,4]
let b: [String] = ["a", "b", "c", "d"]
let c = [a, b]
println(c[0])
/*
(
1,
2,
3,
4
)
*/
println(c[1])
/*
(
a,
b,
c,
d
)
for your plist you could do this:
let a = [1,"a"]
let b = [2, "b"]
let c = [a, b]
println(c[0])
/*
(
1,
a
)
*/
println(c[1])
/*
(
(
2,
b
)
*/
if you use NSCoding, you prearrange all the data any way you want and get back in that form.
NSUserDefaults - How can I store an array of custom objects (Goals)