You might well have had a terminal on your desk, because that had been an increasingly common thing for over a decade by 1981. But probably nothing fun on it in a government/military setting.

My dad had a computer on his desk in 1979. It was a Z80 based business computer with a monochrome monitor, 5.25" floppy drive, and a dot matrix printer.

It wasn't cheap, but still not a huge investment for a small company.

The person with the calendar seems to have worked at a large defense related operation?

It wouldn't have been a financial stretch for them to have VT-100 terminals on their desks connected to VAX 11/780 superminicomputers as early as 1978.