Steps to reproduce:

Go to http://www.catalog.update.microsoft.com/Home.aspx , find the first Edit box (which might have already gained focus) and type something like the phrase "Windows 10" in it and press Enter to initiate a search, press Control+Home in the newly opened webpage and press T a couple of times to reach the table which reads as "Table updates."

Actual behavior:

If, in this table or in fact in all tables on this page, you press Control+ALT+Left, Control+ALT+Right, Control+ALT+Up and Control+ALT+Down to navigate by column or row, NVDA does nothing and just says: "Not in a table cell."

Expected behavior:

Table navigation keystrokes should work, or if the table doesn't have columns/rows (strangely of course), NVDA should say something like "No table columns" or "No table rows," not something like "Not in a table cell." This table indeed has rows so CTRL+ALT+Up/Down should function as expected.
Even if you go to the page http://www.catalog.update.microsoft.com/Home.aspx itself and locate its tables, you'll see that table navigation shortcuts don't work.

System configuration:

IE 11 and Chrome 67 64-Bit

NVDA Installed/portable/running from source:

Installed

NVDA version:

2018.1, 2018.2.

Windows version:

Windows 7 and 10, both Pro and 64-Bit

Name and version of other software in use when reproducing the issue:

Other information about your system:

Other questions:

Does the issue still occur after restarting your PC?

Yes

Have you tried any other versions of NVDA?

Yes -- as mentioned above