Hi, my guess is that it's an 128KB expansion card.
Such cards existed to expand motherboard memory from 512 KB to 640 KB.
This one has a selectable starting address, so it likely can be used to have upper mempory, too.
Depending on the range (-it looks like a full 16/24-Bit ISA card-) of that it might also work as an Extended Memory card.
So the starting address can be above 1 MB, maybe.
If it has 128 KB of RAM, then it would be enough to provide those ~64 KB of high memory (HMA).

Edit: Hm. The chips are GM71C1000 and have 1M x 1bit and there are 18 of them.
According to this table each has 128KB of RAM:
https://alxlab.com/dram/index?sort=part_number
So maybe it's an 1 MB RAM card of some sort?
That "x128" knob might define the starting adress in 128 KB steps (two 64KB segments).

Edit: Hm. It has a knob labeled "MS i/o port".
So maybe it's an EMS card? An XMS card wouldn't need a control port, I think.

With 18 x chips that are 1mbit x 1, it has 2MB + parity. All of the chips that I looked at on the card have 1990 date codes other than the Goldstar memory chips which are from 1991. So, it was either originally just a 1MB card and was expanded after purchase, or it was built as a 1MB card but was stored for a while and later upgraded and sold as a 2MB card.

I don't have much experience with these, but I'm with Jo22 in thinking this is an EMS card.

Looks like both XMS and EMS...

In XMS mode, STARTING ADDRESS selectable for the entire range of ISA addressing, up to 15 MEGA + 7 X 128 KB.
8 X 128 KB and 9 X 128 KB positions probably don't make sense...

In EMS mode, MS I/O PORT is obvious.

What exactly is written above the SW4 (LINE...)?

Anyway, I would simply install that card in some machine with less than 16 MB, only setting the STARTING ADDRESS switches.
If the card happens to be configured for XMS mode, the extra 2 MB should just show up.
If it doesn't show up, it must be in the EMS mode - tough luck, needs further investigation, and hunting for some elusive EMS driver...

Interesting card, there is a good chance to get it running. I also think it can do XMS+EMS.

For XMS the starting adress seems to be selected with the "X128KB" and the "MEGA" selector to choose a starting adress. You need to select the starting adresss to start right behind the RAM on your mainboard.

See also here, the testext.exe program is very useful to test such cards:
ISA XMS/EMS Memory Extension / Expansion cards: Now Running without Driver / Documentation :-)

EMS will be more difficult as you need to find a driver for your specific card...