Can someone explain why Jesus was put into a tomb rather than being left on the cross or put into a common grave.
The fact that he was crucified and then given a honourable burial is part of my confusion.
I think the answer is much simpler than you realise.
Our Lord died in the afternoon of the Friday; around 3pm. In April this would give perhaps four hours before sundown. As has already been said, Jews are not permitted to work on the Sabbath, and so the burial would have to happen either before sundown on the Friday, or wait until the Saturday evening or Sunday. This does not leave enough time to dig a grave and carry out full burial rituals.
Clearly, the Lord's followers did not want the body lying around unburied, and Joseph of Arimathea, as an influential man, was able to find a solution. He already had a tomb, and he had the right connections with the Romans to get permission to put the body into it.
There is no reason to suppose this tomb had room for only one person; it might have been large enough for several, and Joseph and other family members could still have been placed there in due course of time. We know it was cut from the solid rock, and we know it was covered by a large stone, so it was not small.
Joseph was able to get permission to put the body into the tomb, and was able to ensure it was wrapped appropriately, which implies the body was first washed, and then the tomb was sealed. That was as much as could be done before the Sabbath. We know this because the women returned to the tomb on the Sunday evening, as the Sabbath ended, in order to complete the rituals by annointing the body properly.
In other words, this was the best solution to a very difficult problem at the time. What happened on the Friday was not a complete burial, because part of the ritual remained for the Sunday, but it was the best that could be done.