1 row = 1 entity.
Each column may contain:
- a state (
sensor.my_sensor.state); - an attribute’s value (
sensor.my_sensor.my_attribute); - a processed state’s value (
Foo(sensor.my_sensor.state)); - a processed attribute’s value (
Foo(sensor.my_sensor.my_attribute)),
but not these:
- a combination of a state & attributes (
sensor.my_sensor.state + sensor.my_sensor.my_attribute + sensor.my_sensor.my_attribute_2); - data from another sensors.
Means - you need to PREPARE data before displaying them in flex-table-card - probably define a template sensor with attributes storing all your data.
Update: check this also and this.