What's the BLE communication speed? How many bytes can BLE send one time?

[KKIM.6]

I found that the output data is 8 bit (1 byte) with 247 arrays in a BLE example.

So, is 247 bytes maximum value to send data one time through BLE?

if so, I heard BLE can send 1 Mbyte per second. What is this?

Does it mean BLE can communicate to the client about 4000 times per second?

[KKIM.6]

I recently upgraded my laptop's wireless module using AX210NGW which affords BLE 5.2. I can feel data transfer speed increases in the Window BLE Explorer app.