You can, in theory, use IFormDataRepository to load submissions. Could be a bit tricky though 

Thanks so much, Quan.

Could you elaborate a bit more about IFormDataRepository? Can I directly DI its instance into my block component?

And do we have any documents or articles for getting some details?

This came up before here: https://world.optimizely.com/forum/developer-forum/CMS/Thread-Container/2017/5/programetically-getting-episerver--forms--submitted-data/

Sample code from Dejan there:

List<Submission> submittedData = _formDataRepository.GetSubmissionData(
    new FormIdentity(formGuid, languageBranch),
    DateTime.Now.AddDays(-100),
    DateTime.Now).ToList();

It is tricky because there is no method to load form(s) submitted by a specific user. You can, in theory, use DDS directly to get those data, but it'll be non trivial