The number of the Fuzzy Rule Interpolation (FRI) applications in engineering tasks is still insignificant compared to the classical fuzzy reasoning methods. The main goal of this paper is to emphasize the benefits of the direct (embedded) applicability of fuzzy rule interpolation and the related sparse rule-based knowledge representation through demonstrative examples in rather different areas. As a prerequisite of sparse rule-base application in fuzzy system the FRI methods have the benefit of providing reasonable (interpolated) conclusions even if none of the existing rules matches the current observation. In spite of the classical fuzzy reasoning methods this feature enables FRI systems to have knowledge representation similarly constructed as expert systems, built upon the definition of cardinal rules only. On the other hand, thanks to the fuzzy concept, the fuzzy set symbol representation and the fuzzy reasoning, the discretely defined rules can act on continuous universes and continuous states. After a short discussion of FRI methods the paper will briefly introduce four FRI embedded application example of rule-based knowledge representation acting on continuous domain problems selected from the last 15 years work of our research group.