This is what DataFrames does. Perhaps, IndexedTable could use the same formatting with an additional field for showing whether variable is a primary key or not.
julia> describe(df)
2×8 DataFrame
│ Row │ variable │ mean │ min │ median │ max │ nunique │ nmissing │ eltype │
│ │ Symbol │ Float64 │ Real │ Float64 │ Real │ Nothing │ Nothing │ DataType │
├─────┼──────────┼─────────┼────────┼─────────┼────────┼─────────┼──────────┼──────────┤
│ 1 │ year │ 1923.5 │ 1875 │ 1923.5 │ 1972 │ │ │ Int64 │
│ 2 │ value │ 579.004 │ 575.96 │ 579.12 │ 581.86 │ │ │ Float64 │
This is what DataFrames does. Perhaps, IndexedTable could use the same formatting with an additional field for showing whether variable is a primary key or not.