Adding data from IoT Core to TimeStream with Rules. Strange table column

I am pushing this message style to Iot Core:

#test/testing
{
  "sensor_id": "28-3ce104579319",
  "value": 33.312
}
#test/testing
{
  "sensor_id": "28-011921d74ee8",
  "value": 21.875
}
#test/testing
{
  "sensor_id": "28-3ce10457469c",
  "value": 56.0
}
#test/testing
{
  "sensor_id": "28-011921dac0de",
  "value": 21.75
}

I configured a rule like this to write into timestream.

SQL statement
SELECT sensor_id, value FROM 'test/testing'

I added this table to Grafana. And I can see records. But I am confused why I see this records in the yellow box marked. Why is this in the database? It doesn't make any sense to me. Did I made a mistakte somewhere? Or is this the normal behavior and why?

Thank you