The design standard is that buttons at the top of tab listings generate individual transaction forms (like receipts and payslips) or subsidiary ledgers (like bank accounts and customers) matching the tab’s functional purpose. Buttons at the bottom launch processes (like imports, batch operations, exports, and conversions).
Inexpert users find the simplest operations at the top, in the most obvious place. This way, the program avoids confusing the novice with unnecessary complexity. (Despite what you say, @dalacor, importing a bank statement involves quite a bit more than entering a receipt, even if it gains efficiency with higher volumes.) More advanced users find their shortcuts at the bottom. Importantly, none of the buttons at the bottom are essential functions, only conveniences. Every tab can be successfully and fully used without touching any of the buttons at the bottom. This is good interface design. Manager wasn’t always so consistent in this respect, but has progressed steadily in that direction over time.