When I receive a proof for a manuscript, it is always for the main text. But do journals also allow changes to made to the Supplementary Tables/Figures if there are some typos?
It depends on the policies of the journal or publisher to which you have submitted your research manuscript. Some journals allow changes to supplementary data during the post-acceptance proofing stage, while others may not.
If you need to make any changes to your supplementary data after acceptance, it is always best to check with the journal's editorial office to see if they allow such changes. Some journals may also require you to submit a formal request for making changes to the supplementary data, and they may have specific guidelines for doing so.
In any case, it is important to ensure that any changes you make to your supplementary data are necessary and justified and that they do not affect the overall conclusions or scientific validity of your research.