There are some generators available in Nerval Reports and, although the choosing process could be trivial sometimes, some guidance in this could be useful. The first thing that you should think when choosing a generator is: which file formats I need my reports to be generated? Currently, Nerval Reports support creating .pdf, .csv, .html and .tex. Bellow is the matrix of target file format for each available generator:

Generator	Target format(s)
csv-generator	.csv
html-generator	.html .pdf(*)
pdf-generator	.pdf
tex-generator	.tex .pdf(**)

    As you can see, the only point of doubt would be when you desire to generate PDF reports, which could be obtained by multiple ways. If you just want to export to PDF the best choice is pdf-generator. But many factors could influence your choose: performance, file size, available to install third party libraries or applications and multiple report format support with a single generator. The bellow matrix could be a guide to you on those questions.

Generator	File size	Performance	File size (for large reports)	Performance (for large reports)	Depends on external apps
html-generator + html-pdf-flying-saucer-converter	Normal	Normal	Normal	Really Bad	No
pdf-generator	Normal	Good	Small	Great	No
tex-generator + tex-pdf-converter	Normal	Good	Smallest	Good	Yes (TeTeX)