Tom answered my request for what meaning scholars have derived from all the numbers in Mark 8:
"By the five loaves are figured the Five Books of Moses, by the two fishes, the Psalms and Prophets."
"Or the two fishes are the discourses of fishermen, that is, their Epistles and Gospel."
Or "by the five thousand men are meant those who, living in the world, know how to make a good use of external things."
Or "by the twelve baskets, the Apostles and the following Doctors are typified, externally indeed despised by men, but inwardly full of healthful food. For all know that carrying baskets is a part of the work of slaves."
"Or, in the gathering of the twelve baskets full of fragments, is signified the time, when they shall sit on thrones, judging all who are left of Abraham, Isaac, and Jacob, the twelve tribes of Israel, when the remnant of Israel shall be saved."