The size restriction as far as I know is 4MB not 2MB, please check again. If you are bit clever and creative you can add all your documents into a single pdf without going over the size limit. One of my friends managed to create a 51 Page PDF document as a Letter of Explanation for their Study Visa (2nd attempt), and I am not joking I have seen the doc, it has a mix of ~10 pages of detailed explanation and the rest are all images including bank statements, all educational semester-wise transcripts, educational certificates, GRE score card, WES report, IELTS, all work experience letters, pay stubs etc.
Some tips below.
1. Decrease the size of all images using MS Paint . If you already have a pdf doc with the images and the pdf size is still big, take a screenshot/s (print screen) copy the image/s to MS Paint and resize the image/s and copy this image/s to MS Word and save as a new pdf, that should reduce the size by a bit.
2. Use PDFsam to merge, cut, join, split different PDF files. IF the files you have are in JPEG format then do the MS WORD conversion above to convert to a PDF file.
3. You can also use FOX PDF (Trail Version - valid for 15 days free), to resize the PDF by adjusting the DPI, experiment to see which dpi offers the lowest size while preserving image quality to the extent it remains legible to the Visa officer.
4. If the file size is still bigger than 4MB, then you can do one other thing. Move all Financial Documents into the Funds section (attach as one document), now in your Letter of Explanation, in the funds section page you can say "please refer to the Funds section for financial docs/proofs (you can type this in MS Word, covert to PDF and add this as a page, this should hardly take up any space).