Going directly from undergraduate to Ph.D can be a good idea for many students interested in research, but it’s not the only route or the best choice for everyone.
As I wrote before, for students that discovered their interest in theoretical CS late in their undergrad, or perhaps after they graduated, a research Masters, can be a great option. This is particularly the case if the program is funded (i.e., students get a stipend and don’t need to pay tuition). Such programs are not common in the U.S., but there are some excellent choices around the world.
Since (as far as I know) there is no single source listing such programs, I thought a crowdsourced Google spreadsheet might be useful and so created one here: http://tiny.cc/tcsmasters (Update 11/19/20: this is now pointing to the new sheet created by Aviad Rubinstein and matt Weinberg)
Windows On Theory 
I guess other Israeli universities would qualify, e.g.:
Tel Aviv University (TAU): “we have a Full time dedication Scholarship” : https://www.cs.tau.ac.il/computer/msc
Hebrew University (HUJI): “Fellowships to excelling students” : https://www.cs.huji.ac.il/academics/programs-for-masters-degree ; https://drive.google.com/file/d/1DZUsGXwVRWqiRMDV9MrqztoCJwZw-MHS/view [in Hebrew]
Thank you! Please also add this to the google form if you haven’t already