Using symbolic references:

@A = 1 .. 100;;

@{"a$_"} = @A[ $_*10 .. ($_+1)*10-1 ] for 0 .. $#A/10;;

print @{"a$_"} for 0 .. 9;;
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
[download]

Using an AoAs:

@B = 1 .. 100;;

@{ $subarry[$_] } = @B[ $_*10 .. ($_+1)*10-1 ] for 0 .. $#B/10;;

print "@{ $subarry[ $_ ] }" for 0 .. $#B/10;;
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100

pp \@subarry;;
[
  [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
  [11, 12, 13, 14, 15, 16, 17, 18, 19, 20],
  [21, 22, 23, 24, 25, 26, 27, 28, 29, 30],
  [31, 32, 33, 34, 35, 36, 37, 38, 39, 40],
  [41, 42, 43, 44, 45, 46, 47, 48, 49, 50],
  [51, 52, 53, 54, 55, 56, 57, 58, 59, 60],
  [61, 62, 63, 64, 65, 66, 67, 68, 69, 70],
  [71, 72, 73, 74, 75, 76, 77, 78, 79, 80],
  [81, 82, 83, 84, 85, 86, 87, 88, 89, 90],
  [91, 92, 93, 94, 95, 96, 97, 98, 99, 100],
]
[download]