A feature that lets you group fields by context. As simple as that.
Above is an extreme mvp, but i guess it should be something in that path.
How does is solve the user problems?
It would help creators manage fields when a table gets huge (in columns).
It would be easier for anyone to better understand the table schema.
How was this validated?
I am using Airtable in my team with a lot of people getting to know the base and sometimes it is overwhelming for them to process every column in their minds. It is not visual and I had to do it outside to show them.
I know it could be viewed as many 1:1 relations, so one could say "the user should create new tables". OK, but then there are some problems
If the user needs to access those info in the table (for filters, calculations or interface designing, lets say) it would have to lookup these fields - the problem would still exist.
Who is the target audience?
I think every member on a team with creators that are heavy users.