Besides RVW, there are many arrangements by Grainger, Holst, Butterworth, Warlock etc.

There are also lots of songs which aren't strictly traditional, but which nevertheless still fit into the folk club repertoire (some are older than many "trad" songs). Arrangements which I've sung include:

Just as the tide eas turning - RVW,
Linden Lea - RVW,
Swansea Town (original of "The Holy Ground") - Holst,
Bring us in good ale - - Holst,
Diverus and Lazarus - Holst,
I love my love - Holst,
No John, No, - Various,
Tom Bowling - Dibden,
Cherry Ripe - Campion(?),
Tomorrow shall be my dancing day - Willcocks.

Oxford University Press publish several books of "Folk Songs for Choirs which contain many of the above.