大阪へ行けば、たこ焼きをたべています。

The conditional form can be used for a condition that happens often, and always has the same result.

大阪へ行けば、たこ焼きをたべています。
Whenever I go to Osaka, I eat takoyaki.

Note the conditional form has no tense, so the same form is used for something that used to happen.

大阪へ行けば、たこ焼きをたべていました。
Whenever I went to Osaka, I would eat takoyaki.