The Galaxy A series of smartphones are usually a range of three - the A3, the A5 and the A7. The Galaxy A5 (2016) that arrived in December 2015 had a model number of SM-A510. That page apparently confirms the existence of the A5 (2018).
It is also being speculated that Samsung may use Qualcomm's Snapdragon 845 SoC which could be seen as a stiff competitor to the Exynos 9810 SoC, in its Galaxy S9 products. It was considered that Samsung will launch this processor along with the launch of S9.
The source - Ice Universe - has previously leaked information about new Samsung devices which have turned out to be correct, so the odds are likely that Samsung are working on a Samsung Galaxy S9 Mini device. However, the listing of the phone does not contain any details on its specs. Since the phone will be arriving with a full screen design, its fingerprint scanner will be present on its rear panel.
In addition, the phone is also expected to have an IP68 certification for dust and water resistance. The Galaxy A5 has also been spotted on GeekBench running the Exynos 7885 chipset coupled with 4GB RAM.
The report adds the Samsung Galaxy A7 2018 got FCC approval on November 9. So there is a chance the Galaxy A series for 2018 could come with a new "Infinity Display" without any home button on the front. Both the smartphones are also speculated to feature a dedicated button for accessing Bixby AI.
There was word of Samsung producing an S8 Mini earlier in the year but that turned out to be either an elaborate prank by the South Korean company, or an unfeasible endeavour due to a number of reasons. Talking about the RAM, Galaxy J3 (2018) will have 2GB RAM with 16GB internal storage. The screen size is expected to be just under 5-inches. Let us know in the comments section below.