This is the 12419th most frequent Russian word.
квадратах
"Квадратах" means "squares" (plural, in prepositional case).
In this sentence, 'в квадратах' indicates the shapes or grid-like arrangement in which the drawings were organized.
На полу были рисунки в квадратах.
There were drawings in squares on the floor.
Here, 'в квадратах' refers to the grid in which the painting is segmented for practical coloring purposes.
Картина нарисована в квадратах для удобства раскрашивания.
The painting was drawn in squares for easier coloring.
In this usage, 'в квадратах' signifies the division of the table into square-shaped sections to enhance visual comprehension.