cmevla is the morphological class of Lojban words that end in consonants. cmevla can be used as names, and have very few other uses in Lojban.
Lojban names can be of two sorts,
1) A series of one or more cmevla
2) A single selbri, of arbitrary complexity.
Often, when lojbanizing a natural language name that ends in a vowel, an arbitrary consonant is added to the end. For whatever reason, "s" is the most common. Anything else would be as fine a choice.
All of the above is pretty straightforward, but made more complicated by older sources that use the term "cmene" for both what is described here as cmevla, and for names in general. Confusion from that is why you sometimes hear the idea that "all names in Lojban end in 's"", etc. That's also why the term "cmevla" was created.