How to fill area in table, including gutter between cells?

[Ujjwal_Jyoti_Goswami]

Use inset instead to adjust your table cell size:

#table(
  inset: 0.5cm,
  columns: 2,
  stroke: none,
  [Normal],[Row],
  table.cell([Join], fill: gray),table.cell([me], fill: gray)
)

Here is the result:

Adjust the value inset: 0.5cm according to your requirement or You can apply selectively for either x or y like inset:(y:0.5cm). gutter is the gap between cells, hence wont get colored since only cells are being styled, whereas inset is the padding, hence whole cell along with the padding area will get applied with the style.