perf: Skip observing style-changes

.changeset/quiet-grids-focus.md

@@ -0,0 +1,5 @@
+---
+"@navikt/ds-react": patch
+---
+
+DataGrid.Table: Keyboard navigation no longer rebuilds the internal grid map on every arrow key press, improving responsiveness in large tables.

@navikt/core/react/src/data/table/hooks/useGridCache.ts

@@ -5,7 +5,9 @@ import { type GridCache, buildTableGridMap } from "../helpers/table-grid-nav";
 /**
  * Manages the table grid cache and observes DOM changes that require grid rebuilding.
  * Watches for structural changes (rows/cells added/removed) and attribute changes
- * (colspan, rowspan, hidden, style) that affect grid layout and focusability.
+ * (colspan, rowspan, hidden) that affect grid layout.
+ * Inline `style` is intentionally not observed: focus navigation writes
+ * scroll-margin on every move, and the grid never reads styles.
  */
 function useGridCache(tableRef: HTMLTableElement | null, enabled: boolean) {
   const gridCacheRef = useRef<GridCache>({
@@ -34,7 +36,7 @@ function useGridCache(tableRef: HTMLTableElement | null, enabled: boolean) {
       subtree: true,
       childList: true,
       attributes: true,
-      attributeFilter: ["colspan", "rowspan", "hidden", "style"],
+      attributeFilter: ["colspan", "rowspan", "hidden"],
     });
 
     return () => {