There is a way. In your profile's activity page, there is a section named "tags". The posts you have written and tag wise score is given in that section.
Update for revision 2:
Only way to find out is finding through the votes section from our profile manually. There is no way to find the votes we have cast on others posts by tag wise.
As, the voting system is secretive, there is no way to find it through SEDE too.
The final answer to your question of finding out is "No. There is no way to find out the votes you cast on a particular tag".