7 Vert

import 'package:flutter/material.dart';

SizedBox(
  width: 140,
  child: Table(
    columnWidths: const {
      0: FixedColumnWidth(20),
      1: FlexColumnWidth(),
      2: FixedColumnWidth(30),
    },
    children: [
      buildLegendItem(Colors.black, 'Obsidian', '70%'),
      buildLegendItem(Colors.green, 'Olivine', '20%'),
      buildLegendItem(Colors.purple.shade300, 'Hematite', '5%'),
      buildLegendItem(Colors.red, 'Halite', '5%'),
    ],
  ),
),

TableRow buildLegendItem(Color color, String title, String data) {
  return TableRow(
    children: [
      SizedBox(
        height: 30,
        child: TableCell(
          verticalAlignment: TableCellVerticalAlignment.middle,
          child: Icon(Icons.circle, size: 10, color: color),
        ),
      ),
      TableCell(
        verticalAlignment: TableCellVerticalAlignment.middle,
        child: Padding(
          padding: const EdgeInsets.only(left: 4),
          child: Text(
            title,
            style: const TextStyle(
              fontSize: 14,
              color: Colors.black87,
            ),
          ),
        ),
      ),
      TableCell(
        verticalAlignment: TableCellVerticalAlignment.middle,
        child: Text(
          data,
          style: const TextStyle(
            fontWeight: FontWeight.bold,
            fontSize: 14,
            color: Colors.black87,
          ),
        ),
      ),
    ],
  );
}