ParallelTable is a container module that, in its forward method, applies the ith member module to the ith input, and outputs a table of the set of outputs.

Example: 

mlp= nn.ParallelTable()
mlp:add(nn.Linear(10,2))
mlp:add(nn.Linear(5,3))

require "lab"
x=lab.randn(10)
y=lab.rand(5)

pred=mlp:forward{x,y}
for i,k in pairs(pred) do print(i,k); end
which gives the output: 
1
 0.0331
 0.7003
[torch.Tensor of dimension 2]

2
 0.0677
-0.1657
-0.7383
[torch.Tensor of dimension 3]