Ooops, that is a tricky one!
aa = {{{a, b}, {c, d}, {e, f}}, {{1, 2}, {3, 4}, {5, 6}}}; t = {x, z}; Flatten /@ # & /@ Thread /@ Thread[{aa, t}]
... well, I prefer Davids solution!
Henrik
Here probably the same question: How to insert elements of a list into list of lists?
MapThread[Flatten /@ Thread[{##}] &, {aa, t}]
{{{a, b, x}, {c, d, x}, {e, f, x}}, {{1, 2, z}, {3, 4, z}, {5, 6, z}}}
Thank you a lot !
Flatten always scares me with regards to scalability, thus I prefer
Append @@@ # & /@ Thread /@ Transpose[{aa, t}]
