Hi Chris
I ran into the same issue when building a snapshot table for multiple tables (and ironically, when a user switches phases on a project). My approach was as follows:
1) In the child table: create a formula field that is comma delimited that combines the columns (or the delimiter of your choice) with a newline character at the end
2) In the Relationship screen->Add Summary: Use the new Combined Text summary field to summarize the formula field for all the Child records to the Parent record
3) In the Parent table: Convert the Data to Text in another formula using ToText()
4) Use an Automation to snapshot the Value in a Text field in the Snapshot table.
Now that you have a record or (metadata) of the related record of the child table, you can reconstruct them through string manipulations in a variety of ways using formula fields or Javascript.
For my use case, I used javascript to reconstruct the data.
Can you tell me more about the use case what you are trying to accomplish?
