n8n Data Tables Data Tables are n8n's built-in tabular storage : real tables inside the n8n instance with columns, types, rows, and CRUD via the node and data-table MCP tools. Use them for local persistent state: lookup tables, recent events, per-session inventories, counters, idempotency tracking, dedup state when there's row-level logic or external visibility (plain "have I seen this value?" dedup belongs in the node). Small-to-moderate volume (tens of thousands of rows fine, millions belong in a real DB). Non-negotiables 1. System-managed columns + external IDs. Three columns auto-exist on…