Hi Alexey,
Thanks for using Syncfusion products.
I am afraid that i am not able to reproduce the issue that you have mentioned here. I am able get the grid object using "GetEGridTable" method.
Please refer the sample from the below link, for hiding a column:
http://websamples.syncfusion.com/samples/Grid.Web/6.4.0.15/GGC_Web_HideColumn/main.htmPlease try this, and let me know if you have any other concerns.
Regards,
Raji