Hi Rubens,
Here is one way
sorted = Table[{i, j, k, Subscript[E, x][i] + Subscript[E, y][j] + Subscript[E, z][k]},
{i, 1, 3}, {j, 1, 2}, {k, 1, 4}] //
Flatten[#, 2] & // SortBy[Last]
Print[Subscript[E, #[[1]], #[[2]], #[[3]]], " = ", #[[4]]] & /@ sorted