If you can play this card it's almost always a good choice, with action advantage and healing wrapped up in a nice package. Of course you are not forced to play a Lore Noldor or Silvan to use it but we often found that Elrond is a good enabler, even letting it heal 4 damage which can help bring someone like Aragorn or Glorfindel up to full health.
Attachment. Cost: 1.
Play only if you control a Noldor or Silvan hero.
Attach to a hero.
Action: Discard Lembas to ready attached hero and heal 3 damage from it.
"...it is more strengthing than any food made by Men, and it is more pleasant than cram, by all accounts. Lórien Elf, The Fellowship of the Ring
Trouble in Tharbad #64. Lore.