BUILT-IN MATHEMATICA SYMBOL

GridBox

GridBox[{{box₁₁, box₁₂, ...}, {box₂₁, box₂₂, ...}, ...}]
is a low-level box construct that represents a two-dimensional grid of boxes or strings in notebook expressions.

Details and Options Details and Options

GridBox is the low-level representation of Grid. Except for low-level notebook expression manipulation, GridBox should not need to be used directly.
In a notebook, columns of a GridBox can be added using Ctrl+, and rows using Ctrl+Enter.
Ctrl+, or a menu item can be used to start building a GridBox.
You can use tab to move from one entry in a GridBox to the next. Ctrl+Space moves out of the whole GridBox.
In StandardForm and InputForm, GridBox[list] is interpreted as list.
You can place parentheses around a GridBox to make it look more like a matrix, but these are by default ignored when the GridBox is interpreted.
The following options can be given:

AllowedDimensions	Automatic	restrictions on number of rows or columns
BaselinePosition	Automatic	the position of the baseline for the whole grid
ColumnAlignments	Center	how to align columns
ColumnLines	False	whether to draw lines between columns
ColumnsEqual	False	whether to make all columns equal width
ColumnSpacings	0.8	spacings between columns in ems
ColumnWidths	All	actual widths of columns in ems
GridDefaultElement	""	what to insert when a new entry is created
RowAlignments	Baseline	how to align rows
RowLines	False	whether to draw lines between rows
RowMinHeight	1.0	the minimum total row height in x heights
RowsEqual	False	whether to make all rows equal total height
RowSpacings	1.0	spacings between rows in x heights

GridBox is a low-level construct that works only for two-dimensional arrays; TableForm and MatrixForm are higher-level constructs that can also be used for higher-dimensional arrays.
In StandardForm, explicit GridBox objects are output literally. You can use DisplayForm to see the display form of such objects.