I cannot think off the top of my head how to get that, but this would give you an array of arrays.
ruby { code => "
i = event.get('find_id')
t = event.get('find_@timestamp')
a = []
i.each_index { |k|
n = [ i[k], t[k] ]
a << n
}
event.set('arrayOfArrays', a)
"
}