Definitions for grab bag
Random House Webster's College Dictionary
a bag or container from which a person, as at a party, draws a gift without knowing what it is.
any miscellaneous collection.
Origin of grab bag:
an assortment of miscellaneous items
a container from which a person draws a wrapped item at random without knowing the contents
a gift, purchase, etc. whose contents are concealed until after a selection is made
any random assortment, selection or possibility
Origin: From grab + bag.