grab bag

Short definition from Wiktionary

Noun

1. 1
   A gift, purchase, etc. whose contents are concealed until after a selection is made; a bag as gift that comprises mystery prizes.
2. 2
   A bag from which a gift or prize may be withdrawn (grabbed) unseen.
3. 3
   Any random assortment, selection or possibility.
4. 4
   A moderately large bag of crisps or other snack, suitable for sharing.
5. 5
   A bag containing essential items, which can be easily picked up and taken in an emergency.
6. 6
   Alternative spelling of grab bag.