Hello Dragan. We do have a feature that can auto-delete rows, designed for high-volume webhooks. However, this is available only on the Enterprise plan (https://www.clay.com/pricing).
That said, when the limit is hit, Clay should return a 403 response, "Record limit reached". You would need to use that as signal to create/swap to a new webhook endpoint.
I recognize this isn't ideal today, but I've made sure we have this use case captured for future product improvements around notifications/alerting, more generally.