grammar - でございまして in this sentence?

それが困ったことに、次はスープでございまして。

Now that I think of it, I had jotted down another sentence that looks like the same :

海外では魔女はとても人気のあるカテゴリーでしてね

Why are ございます and です conjugated that way ?

Answer

Japanese is a rare language in that it is often the listener/reader (instead of the speaker/writer as in English) who must finish the sentence and understand exactly what the speaker/writer would have wanted to say. Not saying everything is a virtue in the Japanese culture whereas saying everything as clearly as possible is a virtue in many others.

For that reason, you will keep encountering "sentences" ending with conjunctions and verbs/adjectives in the te-forms for as long as you study Japanese. We call those 「言{い}いさし表現{ひょうげん}」. 「さす」 is 「止す」 in kanji, but you do not have to know that as it is rarely written in kanji. 「さす」 means "to stop (in the middle)", so 「食べさしのハンバーガー」 means a "half-eaten hamburger". The sentence version of that burger is the 言いさし表現, one might say. おもろいこと言うな、ワシも・・

BTW, I have no idea what to call 言いさし表現 in English mainly because it is not a term needed in the English-speaking culture.

Thus, every time one uses an 言いさし表現, one is leaving something unsaid. You as the listener/reader, however, will usually have no problem understanding from the context or situation/occasion what was left unsaid by the other person. Context is of utmost importance in Japanese. What might confuse the beginning Japanese-learners the most, however, is the fact that what is left unsaid would almost always be the main clause.

So, what kinds of things are most often left unsaid in 言いさし表現? Those would generally be explanations of matters, exclamations, apologies, gratitude and criticism.

Finally, though I wish to tell you what is left unsaid in your example sentences, I could not do so for the complete lack of context.

「それが困{こま}ったことに、次{つぎ}はスープでございまして。」

= "Unfortunately, the next course is the soup..."

I have no idea in what situation someone might say this. It sounds like the speaker is being apologetic, but that would be all I could say.

Context is everything in 言いさし表現.

Next,

「海外{かいがい}では魔女{まじょ}はとても人気{にんき}のあるカテゴリーでしてね」

= "Witches are a very popular category abroad..."

Again, without context, I have no idea what type of phrase would follow here. All I could guess would be some kind of explanation.