A police spokeswoman said the offenders fled on foot and have not yet been located.
The tablet was recovered at the intersection of Te Mata Rd and Simla Ave.
A Hastings Taxis spokeswoman confirmed it was their driver involved, but declined to comment further due to the ongoing police investigation.
A St John Ambulance spokeswoman said a man was transported to Hawke's Bay Hospital in a serious condition after the attack.
A Hawke's Bay District Health Board spokeswoman said the man in his 40s is now in a stable condition at hospital.
New Zealand Taxi Federation executive director John Hart said the "cowardly attack" on a lone taxi driver highlights the importance of having functioning cameras for all small passenger vehicles.
"While most taxis are required to have working cameras, others are not and attacks such as these highlight the importance of cameras," he said.
"Most taxi fares are paid electronically, so there is very little cash and I don't think these gutless wonders would have got too much."
"Fortunately attacks this serious are not common, but there is always a danger," he added.
Hart also said it was a "serious mistake" for the Government to remove the requirement for panic alarms in taxis in 2017.
"Panic alarms alert control rooms to a driver in trouble. They can hear what is going on in the vehicle, pinpoint the location and get help quickly," he said.
"That is essential for the safety of drivers."
Police are seeking any information which may assist in locating these offenders.
Anyone who saw anything suspicious in the area around 1am, or has any other information that may help, is asked to contact police on 105 and quote file number 200920/7645.
