View Cell Bounds, Table Markup
The View Cell Bounds and View Table Markup commands display the boundaries of cells and table column and row markup, respectively. With these two options switched on, you can better understand the structure of the table. Switched off, however, you can visualize the table more accurately.
The View Cell Bounds command toggles the display of table boundaries (borders) on and off for tables that have a table border value of 0.
The View Table Markup command toggles the display of the blue column and row markers on and off.