Well, I suppose you do! (You really want to say "aren't they?" rather than "don't I?") And yes, they are. However, as I think Eric was getting at, saying "there is much salt" or indeed "much food" or "much noise" or using "much" like that with any other mass noun is not at all colloquial and sounds formal to the point of being stilted. People just don't say it, which is odd, because there is no such issue with saying the plural counterpart, e.g. "there are many glasses on the table", or using it in the negative, e.g. "there is not much salt on the table".

As a general rule, we use “much” (or “many” in the plural) in the negative, in questions, and when modified by an adverb. In addition, the word “many” is in general use to talk about units of measurement (time, distance etc.). For example: Not much/many. They didn’t eat much food / many hamburgers. Did they eat much food / many hamburgers? How much/many…? So/too much/many. Not much/many. They worked many hours. They walked many miles. Etc. In all other cases, we usually use a lot (of) or lots (of). Note: Native speakers can break these particular "rules" (more like "customs") with impunity, but my advice to ESL learners is that they should first get accustomed to using these rules, and only start to break them after passing a C2 test.

"A lot of" would fit in better; unfortunately, I'm not exactly sure why it sounds right, but English is a strange language. "A lot" or "a lot of" is often used to describe more tangible things, whereas "much" is often used to describe more intangible things - but they are interchangeable. People would understand either sentence, but "there is a lot of salt on the table" sounds more natural to me. (Native speaker, California, USA)