Why is the after-party of a funeral called a 'wake'?

It is not a wake. the wake is at the funeral home where the body is viewed. what you are describing is an after-funeral Supper, possibly this practice ( which is not religious- not a mass or anything like that) might correlate to the Last Supper of Christ and the Apostles- or the related Lutheran term-Lord"s Supper- usually applied to Communion. Not a wake! Come alive!