Fatty acids (E-570) are actually a food but can be used as an anti-caking agent and tablet excipient.
Fat is a subgroup of lipids and consists predominantly of fatty acids as well as a bit of glycerol. A triglyceride consists of a glycerol molecule which is attached to three fatty acids. When we ingest fat, fatty acids are released from the glycerol molecule in the gut with the help of enzymes. The individual fatty acids can have different lengths and properties.
Although fatty acids are closest to being a food, this group of substances has nevertheless been given E-number 570. In dietary supplements, they are typically used as an anti-caking agent and tablet excipient. The group of fatty acids typically includes stearic acid, palmitic acid, oleic acid and myristic acid but may also include other acids found in fat.
There is no quantitative limit on how much fatty acid may be used in preparations which may well contain excipients.
In Pharma Nord's curcumin preparation, the fatty acids are used as emulsifiers, which means that they bind water and fat-soluble substances in the preparation together. This helps to increase the uptake.
In other preparations, the fatty acid content is labelled as the respective oil in the preparation. See this.