Can I accept part of an Israeli estate and reject the debts?

No. Inheritance in Israel is all-or-nothing. You cannot cherry-pick assets while disclaiming the liabilities attached to the estate. If you are concerned that debts may exceed assets, your options are either to accept the inheritance (and rely on the limited-liability protection under the Inheritance Law) or to formally renounce the inheritance entirely. Renunciation must be declared in writing before the Registrar of Inheritances.