You can check the radiation pattern here. Or you can also see the Azimuth and Elevation Antenna Patterns of T310c in the datasheet here. Those figures 2-5 applied to T310c as well. It is omni directional antenna.
@Tony Heung The Knowledge Base article with radiation patterns is a great resource, Thank you very much for sharing the link! Will the article be augmented with 11ax/Wi-Fi 6 AP patterns? At the moment only R750 is there.