I think the "Vacsora" is borrowed from Slavic langs. In Ukrainian dinner is "vecheria"
Would you please explain why "vacsorára" is also good. Someone said that "vacsorára" was even a better translation. Does the verb "várni" require the postposition "ra" added to the nouns? Something like the use of prepositions to wait + for in English, or warten + auf in German.
Várni can work both with -ra and accusative (-t). If I'm waiting for you, that can be "rád várok" (or "várok rád", the word order is not fixed and changes with emphasis), but you can also say "téged várlak" (or "várlak téged" which again carries a different tone from the other). I can say "várok Godot-ra", but I can also say "várom Godot-t" (this is not a typo, it's with an m). "Várni" can also have the connotation of expecting something in which case the form is "várni valamit valakitől" - I expect something from somebody.