Yes. Memories in the pensieve are reusable and capable of being viewed more than once:
In GoF, Harry fell into the Pensieve and Dumbledore's memories witnessing several trials: Igor Karkaroff, Ludo Bagman, and then the Deatheaters that tortured Frank and Alice Longbottom (Neville's parent's). Harry realized that it was a memory and noted the passage of time; so that he experienced not only one memory but several in one sitting. Eventually, Dumbledore joined Harry and removed him from the pensieve, after which Dumbledore proceeded to explain the purpose of the device:
"I use the Pensieve. One simply siphons the excess thoughts from one's
mind, pours them into the basin, and examines them at one's leisure.
It becomes easier to spot patterns and links, you understand, when
they are in this form." -- Goblet of Fire, Chapter 30
Dumbledore also make a comment along the line of having so many thoughts that he finds it necessary to use the pensieve quite often.
Furthermore, it is even possible to alter one's own memories as seen in HBP, when Slughorn modified the memory that he was ashamed of - though Dumbledore said that it was crudely done. And of course, we know that memories can be altered by others, even against one's will or knowledge by using the Obliviate charm - which Lockhart confessed to doing in CoS and we know that Tom Riddle did to his uncle Morphin and Hoki, the old house-elf, in HBP.