flatten(combine(df, :id, :vals => ByRow(collect∘eachcol) => AsTable), Not(:id))
or if you know :id is unique:
combine(groupby(df, :id), :vals => only => AsTable)
flatten(combine(df, :id, :vals => ByRow(collect∘eachcol) => AsTable), Not(:id))
or if you know :id is unique:
combine(groupby(df, :id), :vals => only => AsTable)