ByRowThenColumn
(^1) (^1) Center Center
1. Entry 1, 1
(^1, ^1) (^2) Center Center
2. Entry 1.1, 2
(^1, ^1, ^1) (^3) Center Center
3. Entry 1.1.1, 3 is very long to show how spanned cols fail
(^1, ^1, ^2) (^3, ^1) Center Center
4. Entry 1.1.2, 3.1
(^1, ^1, ^2) (^3, ^2) Center Center
5. Entry 1.1.2, 3.2